The expenses of the offering, not including the underwriting discount, are estimated at $0.6 million and are payable by us.

Overallotment Option

              We have granted an option to the underwriters to purchase up to 3,150,000 additional shares at the public offering price, less the underwriting discount. The underwriters may exercise this option for 30 days from the date of this prospectus solely to cover any overallotments. If the underwriters exercise this option, each will be obligated, subject to conditions contained in the purchase agreement, to purchase a number of additional shares proportionate to that underwriter's initial amount reflected in the above table.

No Sales of Similar Securities

              We have agreed, with exceptions, not to sell or transfer any common stock for 60 days after the date of this prospectus without first obtaining the written consent of Merrill Lynch, Pierce, Fenner & Smith Incorporated, J.P. Morgan Securities Inc., SunTrust Robinson Humphrey, Inc. and Wells Fargo Securities, LLC.

              Our executive officers and directors and Ares Capital Management and certain of its affiliates have agreed, with exceptions, not to sell or transfer any common stock for 90 days after the date of this prospectus supplement without first obtaining the written consent of Merrill Lynch, Pierce, Fenner & Smith Incorporated, J.P. Morgan Securities Inc., SunTrust Robinson Humphrey, Inc. and Wells Fargo Securities, LLC. Specifically, we and these other persons have agreed, with certain limited exceptions, including with respect to the issuance of our common stock in connection with the Allied Acquisition, not to directly or indirectly

•

offer, pledge, sell or contract to sell any common stock,



•

sell any option or contract to purchase any common stock,



•

purchase any option or contract to sell any common stock,



•

grant any option, right or warrant for the sale of any common stock,



•

lend or otherwise dispose of or transfer any common stock,



•

request or demand that we file a registration statement related to the common stock, or



•

enter into any swap or other agreement that transfers, in whole or in part, the economic consequence of ownership of any common stock whether any such swap or transaction is to be settled by delivery of shares or other securities, in cash or otherwise.

              This lock-up provision applies to common stock and to securities convertible into or exchangeable or exercisable for or repayable with common stock. It also applies to common stock owned now or acquired later by the person executing the agreement or for which the person executing the agreement later acquires the power of disposition. In the event that either (x) during the last 17 days of the lock-up period referred to above, we issue an earnings release or material news or a material event relating to the Company occurs or (y) prior to the expiration of the lock-up period, we announce that we will release earnings results or become aware that material news or a material event will occur during the 16-day period beginning on the last day of the lock-up period, the restrictions described above shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event.

Nasdaq Global Select Market Listing

              The shares are listed on the Nasdaq Global Select Market under the symbol "ARCC."

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Price Stabilization, Short Positions

              Until the distribution of the shares is completed, SEC rules may limit underwriters and selling group members from bidding for and purchasing our common stock. However, the representatives may engage in transactions that stabilize the price of the common stock, such as bids or purchases to peg, fix or maintain that price.

              In connection with the offering, the underwriters may purchase and sell our common stock in the open market. These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in the offering. "Covered" short sales are sales made in an amount not greater than the underwriters' overallotment option described above. The underwriters may close out any covered short position by either exercising their overallotment option or purchasing shares in the open market. In determining the source of shares to close out the covered short position, the underwriters will consider, among other things, the price of shares available for purchase in the open market as compared to the price at which they may purchase shares through the overallotment option. "Naked" short sales are sales in excess of the overallotment option. The underwriters must close out any naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of our common stock in the open market after pricing that could adversely affect investors who purchase in the offering. Stabilizing transactions consist of various bids for or purchases of shares of common stock made by the underwriters in the open market prior to the completion of the offering.

              Similar to other purchase transactions, the underwriters' purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of our common stock. As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market. The underwriters may conduct these transactions on the Nasdaq Global Select Market, in the over-the-counter market or otherwise.

              Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of our common stock. In addition, neither we nor any of the underwriters make any representation that the representatives will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

Passive Market Making

              In connection with this offering, underwriters and selling group members may engage in passive market making transactions in the common stock on the Nasdaq Global Select Market in accordance with Rule 103 of Regulation M under the Exchange Act during a period before the commencement of offers or sales of common stock and extending through the completion of distribution. A passive market maker must display its bid at a price not in excess of the highest independent bid of that security. However, if all independent bids are lowered below the passive market maker's bid, that bid must then be lowered when specified purchase limits are exceeded. Passive market making may cause the price of our common stock to be higher than the price that otherwise would exist in the open market in the absence of those transactions. The underwriters and dealers are not required to engage in passive market making and may end passive market making activities at any time.

Electronic Offer, Sale and Distribution of Shares

              The underwriters may make prospectuses available in electronic (PDF) format. A prospectus in electronic (PDF) format may be made available on a web site maintained by the underwriters, and the

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underwriters may distribute such prospectuses electronically. The underwriters may allocate a limited number of shares for sale to their online brokerage customers.

Other Relationships

              The underwriters and their affiliates have provided in the past to Ares and may provide from time to time in the future in the ordinary course of their business certain commercial banking, financial advisory, investment banking and other services to Ares and its affiliates and managed funds and Ares Capital or our portfolio companies for which they have received or will be entitled to receive separate fees. In particular, the underwriters or their affiliates may execute transactions with Ares Capital or on behalf of Ares Capital, Ares or any of our or their portfolio companies, affiliates and/or managed funds. In addition, the underwriters or their affiliates may act as arrangers, underwriters or placement agents for companies whose securities are sold to or whose loans are syndicated to Ares, Ares Capital or Ares Capital Management and its affiliates and managed funds.

              An affiliate of Merrill Lynch, Pierce, Fenner & Smith Incorporated acted as Allied Capital's financial advisor in connection with the Allied Acquisition.

              Affiliates of the underwriters are limited partners of private investment funds affiliated with our investment adviser, Ares Capital Management LLC.

              The underwriters or their affiliates may also trade in our securities, securities of our portfolio companies or other financial instruments related thereto for their own accounts or for the account of others and may extend loans or financing directly or through derivative transactions to Ares, Ares Capital, Ares Capital Management or any of the portfolio companies.

              We may purchase securities of third parties from the underwriters or their affiliates after the offering. However, we have not entered into any agreement or arrangement regarding the acquisition of any such securities, and we may not purchase any such securities. We would only purchase any such securities if—among other things—we identified securities that satisfied our investment needs and completed our due diligence review of such securities.

              After the date of this prospectus supplement, the underwriters and their affiliates may from time to time obtain information regarding specific portfolio companies or us that may not be available to the general public. Any such information is obtained by the underwriters and their affiliates in the ordinary course of its business and not in connection with the offering of the common stock. In addition, after the offering period for the sale of our common stock, the underwriters or their affiliates may develop analyses or opinions related to Ares, Ares Capital or our portfolio companies and buy or sell interests in one or more of our portfolio companies on behalf of their proprietary or client accounts and may engage in competitive activities. There is no obligation on behalf of these parties to disclose their respective analyses, opinions or purchase and sale activities regarding any portfolio company or regarding Ares Capital to our stockholders.

              Affiliates of certain of the underwriters serve as lenders under our credit facilities and are also lenders to private investment funds managed by Ivy Hill Asset Management L.P., our portfolio company. Certain of the underwriters and their affiliates were underwriters in connection with our initial public offering and our subsequent common stock offerings and rights offering, for which they received customary fees. J.P. Morgan Securities Inc. acted as Ares Capital's financial advisor in connection with the Allied Acquisition. J.P. Morgan Securities Inc. has also been engaged to help us evaluate other various potential strategic acquisition and investment transactions for which it has received and will continue to receive customary fees and expense reimbursement.

              Proceeds of this offering will be used to repay or repurchase outstanding indebtedness under our senior secured revolving credit agreement with J.P. Morgan Chase Bank, N.A., as Administrative Agent. Affiliates of certain of the underwriters are lenders under this revolving credit facility and, therefore, will receive a portion of the proceeds of this offering.

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              Frank E. O'Bryan, one of our independent directors and a member of our audit committee is a stockholder of the publicly traded parent company of one of the underwriters of this offering. As a result, Mr. O'Bryan may be considered an "interested person" of the Company during the pendency of this offering under relevant rules of the Investment Company Act of 1940.

              The principal business address of Merrill Lynch, Pierce, Fenner & Smith Incorporated is One Bryant Park, New York, NY 10036. The principal business address of J.P. Morgan Securities Inc. is 383 Madison Avenue, New York, NY 10179. The principal business address of SunTrust Robinson Humphrey, Inc. is 303 Peachtree Street, Atlanta, GA 30308. The principal business address of Wells Fargo Securities, LLC is 375 Park Avenue, New York, New York 10152. The principal business address of BB&T Capital Markets, a division of Scott & Stringfellow, LLC, is 909 E. Main Street, Richmond, Virginia 23219. The principal business address of BMO Capital Markets Corp. is 3 Times Square, New York, NY 10036. The principal business address of Deutsche Bank Securities, Inc., is 60 Wall Street, New York, NY 10005. The principal business address of Morgan Stanley & Co. Incorporated is 1585 Broadway, New York, NY 10036. The principal business address of UBS Securities LLC is 299 Park Avenue, New York, NY 10171.

Notice to Prospective Investors in the EEA

              In relation to each Member State of the European Economic Area which has implemented the Prospectus Directive (each, a "Relevant Member State") an offer to the public of any shares which are the subject of the offering contemplated by this prospectus may not be made in that Relevant Member State, except that an offer to the public in that Relevant Member State of any shares may be made at any time under the following exemptions under the Prospectus Directive, if they have been implemented in that Relevant Member State:

(a)

to legal entities which are authorized or regulated to operate in the financial markets or, if not so authorized or regulated, whose corporate purpose is solely to invest in securities;



(b)

to any legal entity which has two or more of (1) an average of at least 250 employees during the last financial year; (2) a total balance sheet of more than €43,000,000 and (3) an annual net turnover of more than €50,000,000, as shown in its last annual or consolidated accounts;



(c)

by the underwriters to fewer than 100 natural or legal persons (other than "qualified investors" as defined in the Prospectus Directive) subject to obtaining the prior consent of the representatives for any such offer; or



(d)

in any other circumstances falling within Article 3(2) of the Prospectus Directive;

provided that no such offer of shares shall result in a requirement for the publication by us or any representative of a prospectus pursuant to Article 3 of the Prospectus Directive.

              Any person making or intending to make any offer of shares within the EEA should only do so in circumstances in which no obligation arises for us or any of the underwriters to produce a prospectus for such offer. Neither we nor the underwriters have authorized, nor do they authorize, the making of any offer of shares through any financial intermediary, other than offers made by the underwriters which constitute the final offering of shares contemplated in this prospectus.

              For the purposes of this provision, and your representation below, the expression an "offer to the public" in relation to any shares in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase any shares, as the same may be varied in that Relevant Member State by any measure implementing the Prospectus Directive in that Relevant Member State and the expression "Prospectus Directive" means Directive 2003/71/EC and includes any relevant implementing measure in each Relevant Member State.

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              Each person in a Relevant Member State who receives any communication in respect of, or who acquires any shares under, the offer of shares contemplated by this prospectus will be deemed to have represented, warranted and agreed to and with us and each underwriter that:

(A)

it is a "qualified investor" within the meaning of the law in that Relevant Member State implementing Article 2(1)(e) of the Prospectus Directive; and



(B)

in the case of any shares acquired by it as a financial intermediary, as that term is used in Article 3(2) of the Prospectus Directive, (i) the shares acquired by it in the offering have not been acquired on behalf of, nor have they been acquired with a view to their offer or resale to, persons in any Relevant Member State other than "qualified investors" (as defined in the Prospectus Directive), or in circumstances in which the prior consent of the representatives has been given to the offer or resale; or (ii) where shares have been acquired by it on behalf of persons in any Relevant Member State other than qualified investors, the offer of those shares to it is not treated under the Prospectus Directive as having been made to such persons.

              In addition, in the United Kingdom, this document is being distributed only to, and is directed only at, and any offer subsequently made may only be directed at persons who are "qualified investors" (as defined in the Prospectus Directive) (i) who have professional experience in matters relating to investments falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended (the "Order") and/or (ii) who are high net worth companies (or persons to whom it may otherwise be lawfully communicated) falling within Article 49(2)(a) to (d) of the Order (all such persons together being referred to as "relevant persons"). This document must not be acted on or relied on in the United Kingdom by persons who are not relevant persons. In the United Kingdom, any investment or investment activity to which this document relates is only available to, and will be engaged in with, relevant persons.

Notice to Prospective Investors in Switzerland

              This document, as well as any other material relating to the shares which are the subject of the offering contemplated by this prospectus, do not constitute an issue prospectus pursuant to Article 652a and/or 1156 of the Swiss Code of Obligations. The shares will not be listed on the SIX Swiss Exchange and, therefore, the documents relating to the shares, including, but not limited to, this document, do not claim to comply with the disclosure standards of the listing rules of SIX Swiss Exchange and corresponding prospectus schemes annexed to the listing rules of the SIX Swiss Exchange. The shares are being offered in Switzerland by way of a private placement, i.e., to a small number of selected investors only, without any public offer and only to investors who do not purchase the shares with the intention to distribute them to the public. The investors will be individually approached by the issuer from time to time. This document, as well as any other material relating to the shares, is personal and confidential and do not constitute an offer to any other person. This document may only be used by those investors to whom it has been handed out in connection with the offering described herein and may neither directly nor indirectly be distributed or made available to other persons without express consent of the issuer. It may not be used in connection with any other offer and shall in particular not be copied and/or distributed to the public in (or from) Switzerland.

Notice to Prospective Investors in the Dubai International Financial Centre

              This document relates to an exempt offer in accordance with the Offered Securities Rules of the Dubai Financial Services Authority. This document is intended for distribution only to persons of a type specified in those rules. It must not be delivered to, or relied on by, any other person. The Dubai Financial Services Authority has no responsibility for reviewing or verifying any documents in connection with exempt offers. The Dubai Financial Services Authority has not approved this document nor taken steps to verify the information set out in it, and has no responsibility for it. The shares which are the subject of the offering contemplated by this prospectus may be illiquid and/or subject to restrictions on their resale. Prospective purchasers of the shares offered should conduct their own due diligence on the shares. If you do not understand the contents of this document you should consult an authorised financial adviser.

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LEGAL MATTERS

              Certain legal matters regarding the securities offered by this prospectus supplement will be passed upon for Ares Capital Corporation by Proskauer Rose LLP, Los Angeles, California, Sutherland Asbill & Brennan LLP, Washington, D.C., and Venable LLP, Baltimore, Maryland. Proskauer Rose LLP has from time to time represented the underwriters, Ares and Ares Capital Management on unrelated matters. Certain legal matters in connection with the offering will be passed upon for the underwriters by Fried, Frank, Harris, Shriver & Jacobson LLP, New York, New York.

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PROSPECTUS

$1,000,000,000

Common Stock
Preferred Stock
Debt Securities
Subscription Rights
Warrants

              Ares Capital Corporation is a specialty finance company that is a closed-end, non-diversified management investment company incorporated in Maryland. We have elected to be regulated as a business development company under the Investment Company Act of 1940. Our investment objective is to generate both current income and capital appreciation through debt and equity investments. We invest primarily in first and second lien senior loans and mezzanine debt, which in some cases includes an equity component. To a lesser extent, we also make equity investments.

              We are externally managed by Ares Capital Management LLC, an affiliate of Ares Management LLC, a global alternative asset manager and a Securities and Exchange Commission ("SEC") registered investment adviser with approximately $33 billion of total committed capital as of December 31, 2009. Ares Operations LLC, an affiliate of Ares Management LLC, provides the administrative services necessary for us to operate.

              Our common stock is traded on The NASDAQ Global Select Market under the symbol "ARCC." On January 22, 2010, the last reported sales price of our common stock on The NASDAQ Global Select Market was $12.77 per share. The net asset value per share of our common stock at September 30, 2009 (the last date prior to the date of this prospectus on which we determined net asset value) was $11.16.

              Investing in our securities involves risks that are described in the "Risk Factors" section beginning on page 26 of this prospectus, including the risk of leverage.

              We may offer, from time to time, in one or more offerings or series, up to $1,000,000,000 of our common stock, preferred stock, debt securities, subscription rights to purchase shares of our common stock or warrants representing rights to purchase shares of our common stock, preferred stock or debt securities, separately or as units comprised of any combination of the foregoing, which we refer to, collectively, as the "securities." The preferred stock, debt securities, subscription rights and warrants offered hereby may be convertible or exchangeable into shares of our common stock. The securities may be offered at prices and on terms to be described in one or more supplements to this prospectus. In the event we offer common stock, the offering price per share of our common stock less any underwriting commissions or discounts will generally not be less than the net asset value per share of our common stock at the time we make the offering. However, we may issue shares of our common stock pursuant to this prospectus at a price per share that is less than our net asset value per share (a) in connection with a rights offering to our existing stockholders, (b) with the prior approval of the majority of our common stockholders or (c) under such circumstances as the SEC may permit. This prospectus and the accompanying prospectus supplement concisely provide important information about us that you should know before investing in our securities. Please read this prospectus and the accompanying prospectus supplement before you invest and keep it for future reference. We file annual, quarterly and current reports, proxy statements and other information with the SEC. This information is available free of charge by calling us collect at (310) 201-4200 or on our website at www.arescapitalcorp.com. The SEC also maintains a website at www.sec.gov that contains such information.

              Neither the SEC nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

              This prospectus may not be used to consummate sales of securities unless accompanied by a prospectus supplement.

The date of this prospectus is January 26, 2010.

              You should rely only on the information contained in this prospectus and the accompanying prospectus supplement. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus and the accompanying prospectus supplement is accurate only as of the date on the front cover of this prospectus and the accompanying prospectus supplement, as applicable. Our business, financial condition, results of operations and prospects may have changed since that date.

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ABOUT THIS PROSPECTUS

              This prospectus is part of a registration statement that we have filed with the SEC, using the "shelf" registration process. Under the shelf registration process, we may offer, from time to time, up to $1,000,000,000 of our common stock, preferred stock, debt securities, subscription rights to purchase shares of our common stock or warrants representing rights to purchase shares of our common stock, preferred stock or debt securities, separately or as units comprised of any combination of the foregoing, on terms to be determined at the time of the offering. The securities may be offered at prices and on terms described in one or more supplements to this prospectus. This prospectus provides you with a general description of the securities that we may offer. Each time we use this prospectus to offer securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. As of the date of this registration statement, we had offered $115,069,149 of the $1,000,000,000 of securities covered by this registration statement. Please carefully read this prospectus and the prospectus supplement together with any exhibits and the additional information described under the headings "Available Information" and "Risk Factors" before you make an investment decision.

ii

PROSPECTUS SUMMARY

              This summary highlights some of the information contained elsewhere in this prospectus. It is not complete and may not contain all of the information that you may want to consider. You should read carefully the more detailed information set forth under "Risk Factors" and the other information included in this prospectus. Except where the context suggests otherwise, the terms "we," "us," "our," "the Company" and "Ares Capital" refer to Ares Capital Corporation and its consolidated subsidiaries; "Ares Capital Management" or "investment adviser" refers to Ares Capital Management LLC; "Ares Operations" refers to Ares Operations LLC; and "Ares" refers to Ares Partners Management Company LLC and its affiliated companies (other than portfolio companies of its affiliated funds), including Ares Management LLC, which we also refer to as "Ares Management."

              Other than as specifically set forth herein, information presented with respect to Ares Capital does not reflect the consummation of the Allied Acquisition (as defined below), and any investment decision you make should be made independent of the consummation of the Allied Acquisition. We cannot assure you that the Allied Acquisition will be consummated as scheduled, or at all. See "Pending Allied Acquisition" for a description of the terms of the Allied Acquisition, "Risk Factors—Risks Relating to Our Business—We may fail to consummate the Allied Acquisition" for a description of the risks associated with a failure to consummate the Allied Acquisition and "Risk Factors—Risks Relating to a Consummation of the Allied Acquisition" for a description of the risks that the combined company may face if the Allied Acquisition is consummated.

THE COMPANY

              Ares Capital, a Maryland corporation, is a specialty finance company that is a closed-end, non-diversified management investment company. We have elected to be regulated as a business development company, or a "BDC," under the Investment Company Act of 1940, or the "Investment Company Act." We were founded on April 16, 2004, were initially funded on June 23, 2004 and completed our initial public offering on October 8, 2004. Ares Capital's investment objective is to generate both current income and capital appreciation through debt and equity investments. We invest primarily in U.S. middle-market companies, where we believe the supply of primary capital is limited and the investment opportunities are most attractive. However, we may from time to time invest in larger companies. In this prospectus, we generally use the term "middle market" to refer to companies with annual EBITDA (earnings before interest, taxes, depreciation and amortization) of between $10 million and $250 million. As discussed in "Recent Developments" below, on October 26, 2009, we entered into a definitive agreement (the "Merger Agreement") under which we have agreed, subject to the satisfaction of certain closing conditions, to acquire Allied Capital Corporation ("Allied Capital") in an all stock transaction, which we refer to as the "Allied Acquisition." The Allied Acquisition will be completed in two parts: first, our wholly owned subsidiary, which we refer to as the "merger subsidiary," will merge with and into Allied Capital and second, Allied Capital will merge with and into Ares Capital, which we refer to as the "subsequent combination." We cannot assure you that the Allied Acquisition will be consummated as scheduled, or at all. See "Pending Allied Acquisition" for a description of the terms of the Allied Acquisition, "Risk Factors—Risks Relating to Our Business—We may fail to consummate the Allied Acquisition" for a description of the risks associated with a failure to consummate the Allied Acquisition and "Risk Factors—Risks Relating to a Consummation of the Allied Acquisition" for a description of the risks that the combined company may face if the Allied Acquisition is consummated.

              We invest primarily in first and second lien senior loans and mezzanine debt, which in some cases includes an equity component like warrants. First and second lien senior loans generally are senior debt instruments that rank ahead of subordinated debt of a given portfolio company. These loans also have the benefit of security interests on the assets of the portfolio company, which may rank ahead of or be junior to other security interests. Mezzanine debt is subordinated to senior loans and is generally unsecured. Our debt investments have ranged between $10 million and $100 million each,

1

although the investment sizes may be more or less than the targeted range. Our investment sizes are expected to grow with our capital availability and, if completed, upon consummation of the Allied Acquisition. To a lesser extent, we also make equity investments. Each of our equity investments have generally been less than $20 million, but may grow with our capital availability and are usually made in conjunction with loans we make to these portfolio companies.

              The proportion of these investments will change over time given our views on, among other things, the economic and credit environment we are operating in. In connection with our investing activities, we may make commitments with respect to indebtedness or securities of a potential portfolio company substantially in excess of our final investment. In such situations, while we may initially agree to fund up to a certain dollar amount of an investment, we may syndicate a portion of such amount to third parties, such that we make a smaller investment than what was reflected in our original commitment.

              The first and second lien senior loans generally have stated terms of three to 10 years and the mezzanine debt investments generally have stated terms of up to 10 years, but the expected average life of such first and second lien loans and mezzanine debt is generally between three and seven years. However, we may invest in securities with any maturity or duration. The debt that we invest in typically is not initially rated by any rating agency, but we believe that if such investments were rated, they would be below investment grade (rated lower than "Baa3" by Moody's Investors Service or lower than "BBB-" by Standard & Poor's). We may invest without limit in debt of any rating, as well as debt that has not been rated by any nationally recognized statistical rating organization.

              We believe that our investment adviser, Ares Capital Management, is able to leverage Ares' current investment platform, resources and existing relationships with financial sponsors, financial institutions, hedge funds and other investment firms to provide us with attractive investments. In addition to deal flow, the Ares investment platform assists our investment adviser in analyzing, structuring and monitoring investments. Ares has been in existence for more than 12 years and its senior principals have an average of over 20 years experience investing in senior loans, high yield bonds, mezzanine debt and private equity securities. The Company has access to the Ares staff of approximately 110 investment professionals and to over 150 administrative professionals employed by Ares who provide assistance in accounting, legal, compliance, operations, technology and investor relations.

              While our primary focus is to generate current income and capital appreciation through investments in first and second lien senior loans and mezzanine debt and, to a lesser extent, equity securities of eligible portfolio companies, we also may invest up to 30% of our portfolio in opportunistic investments of non-eligible portfolio companies. Specifically, as part of this 30% basket, we may invest in debt of middle-market companies located outside of the United States, in investment funds that are operating pursuant to certain exceptions to the Investment Company Act, in advisers to similar investment funds and in debt and equity of public companies that do not meet the definition of eligible portfolio companies because their market capitalization of publicly traded equity securities exceeds the levels provided for in the Investment Company Act. We expect that these public companies generally will have debt that may be non-investment grade. From time to time we may also invest in high yield bonds, which, depending on the issuer, may or may not be included in the 30% basket.

              In addition to making investments in the Ares Capital portfolio, our portfolio company, Ivy Hill Asset Management, L.P. ("IHAM"), manages three unconsolidated senior debt funds, Ivy Hill Middle Market Credit Fund, Ltd. ("Ivy Hill I"), Ivy Hill Middle Market Credit Fund II, Ltd. ("Ivy Hill II") and Ivy Hill Senior Debt Fund, L.P. and related vehicles ("Ivy Hill SDF" and, together with Ivy Hill I and Ivy Hill II, the "Ivy Hill Funds") and serves as the sub-adviser/sub-manager for four others: CoLTS 2005-1 Ltd., CoLTS 2005-2 Ltd. and CoLTS 2007-1 Ltd., or collectively, the "CoLTS Funds," and FirstLight Financial Corporation, or "FirstLight." As of December 31, 2009, IHAM had total committed capital under management of over $2.3 billion.

2

              We and GE Commercial Finance Investment Advisory Services LLC also co-manage an unconsolidated senior debt fund: the Senior Secured Loan Fund LLC (formerly known as the Unitranche Fund LLC), or the "SL Fund."

About Ares

              Founded in 1997, Ares is a global alternative asset manager and SEC registered investment adviser with approximately $33 billion of total committed capital and over 250 employees as of December 31, 2009.

              Ares specializes in originating and managing assets in both the leveraged finance and private equity markets. Ares' leveraged finance activities include the origination, acquisition and management of senior loans, high yield bonds, mezzanine debt and special situation investments. Ares' private equity activities focus on providing flexible, junior capital to middle-market companies. Ares has the ability to invest across a capital structure, from senior floating rate debt to common equity. This flexibility, combined with Ares' "buy and hold" philosophy, enables Ares to structure an investment to meet the specific needs of a company rather than the less flexible demands of the public markets.

              Ares is comprised of the following groups:

•

Private Debt Group. The Ares Private Debt Group manages the assets of Ares Capital and Ares' private debt middle market financing business in Europe, Ares Capital Europe ("ACE"). The Private Debt Group focuses primarily on non-syndicated first and second lien senior loans and mezzanine debt, which in some cases may include an equity component. The Private Debt Group also makes equity investments in private middle-market companies, usually in conjunction with loans.



•

Capital Markets Group. The Ares Capital Markets Group manages a variety of funds and investment vehicles that managed approximately $18 billion of committed capital as of December 31, 2009, focusing primarily on syndicated senior secured loans, high yield bonds, distressed debt, other liquid fixed income investments and other publicly traded debt securities.



•

Private Equity Group. The Ares Private Equity Group manages Ares Corporate Opportunities Fund L.P., Ares Corporate Opportunities Fund II, L.P. and Ares Corporate Opportunities Fund III, L.P. (collectively referred to as "ACOF"), which together managed approximately $6 billion of committed capital as of December 31, 2009. ACOF generally makes private equity investments in companies substantially larger than the private equity investments anticipated to be made by the Company. In particular, the Private Equity Group generally focuses on control-oriented equity investments in under-capitalized companies or companies with capital structure issues.

              Ares' senior principals have been working together as a group for many years and have an average of over 20 years of experience in leveraged finance, private equity, distressed debt, investment banking and capital markets. They are backed by a large team of highly disciplined professionals. Ares' rigorous investment approach is based upon an intensive, independent financial analysis, with a focus on preservation of capital, diversification and active portfolio management. These fundamentals underlie Ares' investment strategy and have resulted in large pension funds, banks, insurance companies, endowments and high net worth individuals investing in Ares' funds.

Ares Capital Management

              Ares Capital Management, our investment adviser, is served by a dedicated origination and transaction development team of approximately 34 investment professionals led by the partners of Ares Capital Management, Michael Arougheti, Eric Beckman, Kipp deVeer, Mitchell Goldstein and Michael Smith. Ares Capital Management leverages off of Ares' entire investment platform and benefits from

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the significant capital markets, trading and research expertise of all of Ares' investment professionals. Ares funds currently hold over 700 investments in over 30 different industries. Ares Capital Management's investment committee has nine members, including the partners of Ares Capital Management and Senior Partners of Ares' Capital Markets Group and Private Equity Group.

MARKET OPPORTUNITY

              We believe there are opportunities for us to invest in middle-market companies for the following reasons:

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We believe that as of the date of this prospectus, the recent dislocation in the credit markets has resulted in reduced competition, a widening of interest spreads, increased fees and generally more conservative capital structures and deal terms. Although secondary loan prices have rebounded from historic lows, attractive opportunities to purchase debt in the secondary market continue to exist in certain situations.



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We believe that many senior lenders have, in recent years, de-emphasized their service and product offerings to middle-market businesses in favor of lending to large corporate clients and managing capital markets transactions. In addition, commercial and investment banks are severely limited in their ability to underwrite new financings as they seek to replenish their capital bases and reduce leverage, resulting in opportunities for alternative funding sources.



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We believe there is increased demand among private middle-market companies for primary capital. Many middle market firms have faced increased difficulty raising debt in the capital markets, as commercial and investment banks are capital-constrained and largely unable to underwrite and syndicate bank loans and high yield securities, particularly for middle market issuers.



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We believe there is a large pool of uninvested private equity capital for middle-market companies. We expect private equity firms will seek to leverage their investments by combining equity capital with senior secured loans and mezzanine debt from other sources.



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We believe that as of the date of this prospectus, the recent economic downturn has resulted (and will continue to result) in defaults and covenant breaches by middle-market companies, which will require new junior capital to shore up liquidity or provide new capital through restructuring.



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A high volume of senior secured and high yield debt was originated in the calendar years 2004 through 2007 and will come due in the near term and, accordingly, we believe that new financing opportunities will increase as many leveraged companies seek to refinance in the near term.

COMPETITIVE ADVANTAGES

              We believe that we have the following competitive advantages over other capital providers to middle-market companies:

Existing Investment Platform

              As of December 31, 2009, Ares managed approximately $33 billion of committed capital in the related asset classes of syndicated loans, high yield bonds, mezzanine debt and private equity. We believe Ares' current investment platform provides a competitive advantage in terms of access to origination and marketing activities and diligence for Ares Capital. Specifically, the Ares platform provides the Company an advantage through its deal flow generation and investment evaluation process. Ares Capital's asset management platform also provides additional market information, company knowledge and industry insight that benefits the investment and due diligence process. Ares'

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professionals maintain extensive financial sponsor and intermediary relationships, which provide valuable insight and access to transactions and information.

Seasoned Management Team

              Ares' senior professionals have an average of over 20 years of experience in leveraged finance, including substantial experience in investing in leveraged loans, high yield bonds, mezzanine debt, distressed debt and private equity securities. Ares Capital Management's investment professionals and members of its investment committee also have significant experience investing across market cycles. As a result of Ares' extensive investment experience and the history of its seasoned management team, Ares has developed a strong reputation across U.S. and European capital markets. We believe that Ares' long history in the leveraged loan market and the extensive experience of the principals investing across market cycles provides Ares Capital Management with a competitive advantage in identifying, investing in, and managing a portfolio of investments in middle-market companies.

Experience and Focus on Middle-Market Companies

              Ares has historically focused on investments in middle-market companies and we benefit from this experience. In sourcing and analyzing deals, our investment adviser uses Ares' extensive network of relationships with intermediaries focused on middle-market companies to attract well-positioned prospective portfolio company investments. Our investment adviser works closely with the Ares investment professionals, who oversee a portfolio of investments in over 700 companies, and provide access to an extensive network of relationships and special insights into industry trends and the state of the capital markets.

Disciplined Investment Philosophy

              In making its investment decisions, our investment adviser has adopted Ares' long-standing, consistent credit-based investment approach that was developed over 18 years ago by its founders. Specifically, Ares Capital Management's investment philosophy, portfolio construction and portfolio management involve an assessment of the overall macroeconomic environment, financial markets and company-specific research and analysis. Its investment approach emphasizes capital preservation, low volatility and minimization of downside risk.

Extensive Industry Focus

              We concentrate our investing activities in industries with a history of predictable and dependable cash flows and in which the Ares investment professionals have had extensive investment experience. Since its inception in 1997, Ares investment professionals have invested in over 30 different industries. Ares investment professionals have developed long-term relationships with management teams and management consultants in these industries, and have accumulated substantial information concerning these industries and identified potential trends within these industries. The experience of Ares' investment professionals investing across these industries throughout various stages of the economic cycle provides our investment adviser with access to market insights and investment opportunities.

Flexible Transaction Structuring

              We are flexible in structuring investments, including the types of securities in which we invest and the terms associated with such investments. The principals of Ares have extensive experience in a wide variety of securities for leveraged companies with a diverse set of terms and conditions. We believe this approach and experience enables our investment adviser to identify attractive investment opportunities throughout the economic cycle and across a company's capital structure so we can make investments consistent with our stated investment objective and preserve principal while seeking appropriate risk adjusted returns. In addition, we have the ability to provide "one stop" financing with

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the ability to invest capital across the balance sheet and hold larger investments than many of our competitors. The ability to underwrite, syndicate and hold larger investments (a) increases flexibility, (b) may increase net fee income and earnings through syndication, (c) broadens market relationships and deal flow and (d) allows us to optimize our portfolio composition. We believe that the ability to provide capital at every level provides a strong value proposition to middle market borrowers and our senior debt capabilities provide superior deal origination and relative value analysis capabilities compared to traditional "mezzanine only" lenders.

Broad Origination Strategy

              Our investment adviser focuses on self-originating most of our investments, by identifying a broad array of investment opportunities across multiple channels. It also leverages off of the extensive relationships of the broader Ares platform, including the relationships with portfolio companies held by funds managed by IHAM, to identify investment opportunities. We believe that this allows for asset selectivity and that there is a significant relationship between proprietary deal origination and credit performance. Our focus on generating proprietary deal flow and lead investing also gives us greater control over capital structure, deal terms, pricing and documentation and results in active portfolio management of investments. Moreover, by leading the investment process, our investment adviser is able to secure controlling positions in credit tranches providing additional control in investment outcomes. Our investment adviser also has originated substantial proprietary deal flow from middle market intermediaries, which often allows us to act as the sole or principal source of institutional junior capital to the borrower.

OPERATING AND REGULATORY STRUCTURE

              Our investment activities are managed by Ares Capital Management and supervised by our board of directors, a majority of whom are independent of Ares and its affiliates. Ares Capital Management is an investment adviser that is registered under the Investment Advisers Act of 1940, or the "Advisers Act." Under our amended and restated investment advisory and management agreement, referred to herein as our "investment advisory and management agreement," we have agreed to pay Ares Capital Management an annual base management fee based on our total assets, as defined under the Investment Company Act (other than cash and cash equivalents but including assets purchased with borrowed funds), and an incentive fee based on our performance. See "Management—Investment Advisory and Management Agreement."

              As a BDC, we are required to comply with certain regulatory requirements. While we are permitted to finance investments using debt, our ability to use debt is limited in certain significant respects. See "Regulation." We have elected to be treated for U.S. federal income tax purposes as a regulated investment company, or a "RIC," under Subchapter M of the Internal Revenue Code of 1986, or the "Code." See "Certain Material U.S. Federal Income Tax Considerations."

MARKET CONDITIONS

              Due to volatility in global markets, the availability of capital and access to capital markets has been limited over the last two years. We responded to recent constraints on raising new capital by pursuing other avenues of liquidity and growth, such as adjusting the pace of our investments, becoming more selective in evaluating investment opportunities, pursuing asset sales, developing our third-party asset management capabilities and/or recycling lower yielding investments. We also intend to continue pursuing opportunities to manage third-party funds. As the global liquidity situation and market conditions evolve, we will continue to monitor and adjust our approach to funding accordingly. However, given the unprecedented nature of the volatility in the global markets, there can be no assurances that these activities will be successful. While levels of market disruption and volatility appear to be improving, there can be no assurance that they will not worsen. If they do, we could face

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materially higher financing costs. Consequently, our operating strategy could be materially and adversely affected.

              Consistent with the depressed market conditions of the general economy, the stocks of BDCs as an industry have traded at near historic lows for over twelve months as a result of concerns over liquidity, credit quality, leverage restrictions and distribution requirements. As a result of the deterioration of the market, several of our peers are no longer active in the market and are winding down their investments, have defaulted on their indebtedness, have decreased their distributions to stockholders or have announced share repurchase programs. While market conditions have improved, we cannot assure you that the market pressures we face will not have a material adverse effect on our business, financial condition and results of operations.

              See "Risk Factors—Risks Relating to Our Business."

LIQUIDITY

              We are party to the Revolving Credit Facility (as defined herein) that provides for up to $690.0 million of borrowings (comprised of $615.0 million on a stand-alone basis and an additional $75.0 million in commitments contingent upon the closing of the Allied Acquisition) and up to $897.5 million prior to the closing of the Allied Acquisition, or $1.05 billion after the closing of the Allied Acquisition, if we exercise the "accordion" feature, expires on January 22, 2013.

              In addition, our wholly owned subsidiary Ares Capital CP (as defined herein) is party to the CP Funding Facility (as defined herein) that provides for up to $400.0 million of borrowings, and which expires on January 22, 2013 (with two one year extension options, subject to mutual consent). We use the term "Facilities" to refer to the Revolving Credit Facility and the CP Funding Facility. As of January 22, 2010, we had $315.3 million available for borrowing under our Facilities. As of January 22, 2010, we also had outstanding $273.8 million of CLO Notes (as defined herein) that mature on December 20, 2019. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Financial Condition, Liquidity and Capital Resources."

RISK FACTORS

              Investing in Ares Capital involves risks. The following is a summary of certain risks that you should carefully consider before investing in our securities. In addition, see "Risk Factors" beginning on page 25 for a more detailed discussion of the factors you should carefully consider before deciding to invest in our securities.

Risks Relating to Our Business

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Capital markets have recently been in a period of disruption and instability. These market conditions have materially and adversely affected debt and equity capital markets in the United States, which has had, and may in the future have, a negative impact on our business and operations.



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A failure on our part to maintain our status as a BDC would significantly reduce our operating flexibility.



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We are dependent upon Ares Capital Management's key personnel for our future success and upon their access to Ares' investment professionals.



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Our financial condition and results of operations depend on our ability to manage future growth effectively.



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Our ability to grow depends on our ability to raise capital.



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Regulations governing our operation as a BDC affect our ability to, and the way in which we, raise additional capital.

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We borrow money, which magnifies the potential for gain or loss on amounts invested and may increase the risk of investing with us.



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In addition to regulatory requirements that restrict our ability to raise capital, the Facilities and the CLO Notes contain various covenants which, if not complied with, could accelerate repayment under the Facilities and the CLO Notes, thereby materially and adversely affecting our liquidity, financial condition and results of operations.



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We operate in a highly competitive market for investment opportunities.



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We may be subject to certain corporate-level taxes regardless of whether we continue to qualify as a RIC.



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We may have difficulty paying our required distributions under applicable tax rules if we recognize income before or without receiving cash representing such income.



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We may in the future determine to fund a portion of our investments with preferred stock, which would magnify the potential for gain or loss and the risks of investing in us in the same way as our borrowings.



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We are exposed to risks associated with changes in interest rates.



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Many of our portfolio investments are not publicly traded and, as a result, there is uncertainty as to the value of our portfolio investments.



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The lack of liquidity in our investments may adversely affect our business.



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We may experience fluctuations in our quarterly results.



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There are significant potential conflicts of interest that could impact our investment returns.



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Our investment adviser's liability is limited under the investment advisory and management agreement, and we are required to indemnify our investment adviser against certain liabilities, which may lead our investment adviser to act in a riskier manner on our behalf than it would when acting for its own account.



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We may be obligated to pay our investment adviser incentive compensation even if we incur a loss.



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Changes in laws or regulations governing our operations, or changes in the interpretation thereof, and any failure by us to comply with laws or regulations governing our operations may adversely affect our business.



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We may not replicate Ares' historical success and our ability to enter into transactions with Ares and our other affiliates is restricted.



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We may fail to consummate the Allied Acquisition.

Risks Relating to Our Investments

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Price declines and illiquidity in the corporate debt markets have adversely affected, and may in the future adversely affect, the fair value of our portfolio investments, reducing our net asset value through increased net unrealized depreciation.



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Economic recessions or downturns could impair our portfolio companies and harm our operating results.



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Investments in privately held middle-market companies involve significant risks.



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Our debt investments may be risky, and we could lose all or part of our investment.



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Investments in equity securities involve a substantial degree of risk.

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There may be circumstances where our debt investments could be subordinated to claims of other creditors or we could be subject to lender liability claims.



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Our portfolio companies may incur debt or issue equity securities that rank equally with, or senior to, our investments in such companies.



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When we are a debt or minority equity investor in a portfolio company, we may not be in a position to exert influence on the entity, and management of the company may make decisions that could decrease the value of our portfolio holdings.



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Our portfolio companies may be highly leveraged.



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Our investment adviser's incentive fee may induce Ares Capital Management to make certain investments, including speculative investments.



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Our investments in foreign debt may involve significant risks in addition to the risks inherent in U.S. investments. We may expose ourselves to risks if we engage in hedging transactions.



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We may initially invest a portion of the net proceeds of offerings pursuant to this prospectus primarily in high-quality short-term investments, which will generate lower rates of return than those expected from the interest generated on first and second lien loans and mezzanine debt.

Risks Relating to a Consummation of the Allied Acquisition

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Consummation of the Allied Acquisition will cause immediate dilution to our stockholders' voting interests in us and may cause immediate dilution to the net asset value per share of our common stock.



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We may be unable to realize the benefits anticipated by the Allied Acquisition, including estimated cost savings and synergies, or it may take longer than anticipated to achieve such benefits.



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Our inability to obtain rating agency confirmation and the third party consents of financing providers to us and Allied Capital necessary to complete the transaction could delay or prevent the completion of the Allied Acquisition.



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The Allied Acquisition or subsequent combination may trigger certain "change of control" provisions and other restrictions in certain of our and Allied Capital's contracts and the failure to obtain any required consents or waivers could adversely impact the combined company.



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Several lawsuits have been filed against Allied Capital, members of Allied Capital's board of directors, us and the merger subsidiary challenging the Allied Acquisition. An adverse ruling in any such lawsuit may prevent the Allied Acquisition from becoming effective within the expected timeframe, or at all. If the Allied Acquisition is consummated, these lawsuits and other legal proceedings could have a material impact on the results of operations, cash flows or financial condition of the combined company.



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If the Allied Acquisition does not close, we won't benefit from the expenses incurred in its pursuit.



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Termination of the Merger Agreement could negatively impact us.



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Under certain circumstances, we and Allied Capital are obligated to pay each other a termination fee upon termination of the Merger Agreement.



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The market price of our common stock after the Allied Acquisition may be affected by factors different from those affecting our common stock currently.

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Risks Relating to Offerings Pursuant to this Prospectus

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Our shares of common stock have recently traded at a discount from net asset value and may do so again in the future, which could limit our ability to raise additional equity capital.



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There is a risk that investors in our equity securities may not receive dividends or that our dividends may not grow over time and that investors in our debt securities may not receive all of the interest income to which they are entitled.



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Provisions of the Maryland General Corporation Law and of our charter and bylaws could deter takeover attempts and have an adverse impact on the price of our common stock.



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Investing in our securities may involve an above average degree of risk.



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The market price of our common stock may fluctuate significantly.



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The net asset value per share of our common stock may be diluted if we sell shares of our common stock in one or more offerings at prices below the then current net asset value per share of our common stock or securities to subscribe for or convertible into shares of our common stock.



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Your interest in us may be diluted if you do not fully exercise your subscription rights in any rights offering. In addition, if the subscription price is less than our net asset value per share, then you will experience an immediate dilution of the aggregate net asset value of your shares.



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Investors in offerings of our common stock will likely incur immediate dilution upon the closing of such offering.



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Our stockholders will experience dilution in their ownership percentage if they do not participate in our dividend reinvestment plan.



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You may receive shares of our common stock as dividends, which could result in adverse tax consequences to you.



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Sales of substantial amounts of our common stock in the public market may have an adverse effect on the market price of our common stock.



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The trading market or market value of our publicly issued debt securities may fluctuate.



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Terms relating to redemption may materially adversely affect your return on any debt securities that we may issue.



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Our credit ratings may not reflect all risks of an investment in our debt securities.

RECENT DEVELOPMENTS

Allied Acquisition

              On October 26, 2009, we entered into a definitive agreement to acquire Allied Capital in an all stock transaction valued at $862 million, or approximately $4.61 per Allied Capital share as of January 20, 2010. The boards of directors of both companies have each unanimously approved the Allied Acquisition.

              Allied Capital is an internally managed BDC. Allied Capital invests in primarily private middle-market companies in a variety of industries through long-term debt and equity capital instruments.

              While there can be no assurances as to the exact timing, or that the Allied Acquisition will be completed at all, we are working to complete the Allied Acquisition in the first quarter of 2010. The consummation of the Allied Acquisition is subject to certain conditions, including, among others, Allied Capital stockholder approval, Ares Capital stockholder approval, required regulatory approvals

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(including expiration of the waiting period under the Hart-Scott-Rodino Act Antitrust Improvements Act of 1976, as amended, or the "HSR Act," the early termination of which was granted on December 1, 2009), receipt of certain Ares Capital and Allied Capital lender consents and other customary closing conditions.

              On January 14, 2010, Prospect Capital Corporation ("Prospect Capital") proposed to Allied Capital to acquire all of the issued and outstanding shares of Allied Capital in a stock-for-stock merger. On January 19, 2010, the Board of Directors of Allied Capital unanimously rejected the offer. On January 26, 2010, Prospect Capital renewed its proposal and increased it proposed share exchange ratio from 0.385 Prospect Capital shares for each Allied Capital Share to 0.40 Prospect Capital shares for each Allied Capital Share.

              We cannot assure you that the Allied Acquisition will be consummated as scheduled, or at all (including as a result of any competing offer). See "Pending Allied Acquisition" for a more detailed description of the terms of the Allied Acquisition, "Risk Factors—Risks Relating to Our Business—We may fail to consummate the Allied Acquisition" for a description of the risks associated with a failure to consummate the Allied Acquisition and "Risk Factors—Risks Relating to a Consummation of the Allied Acquisition" for a description of the risks that the combined company may face if the Allied Acquisition is consummated.

Unitranche Fund Acquisition

              In a separate transaction, on October 30, 2009, we completed our acquisition of Allied Capital's interests in the SL Fund for $165 million in cash. The SL Fund was formed in December 2007 to invest in "unitranche" loans of middle-market companies and has approximately $3.6 billion of committed capital, approximately $900 million in aggregate principal amount of which is currently funded. Of the $2.7 billion of unfunded committed capital, approximately $350 million would be funded by us. Since our acquisition of the SL Fund we have made one investment of $11.6 million. Our investment entitles us to a coupon of LIBOR plus 8.0% and certain other sourcing and management fees. In addition, since we invest in the substantial majority of the subordinated certificates in the SL Fund, our underlying investment also entitles us to a substantial portion of the excess cash flows from the loan portfolio.

Ivy Hill SDF Acquisition

              On December 29, 2009, we made an incremental investment in IHAM to facilitate its acquisition of Allied Capital's management rights in respect of, and interests in, the Allied Capital Senior Debt Fund (now referred to as "Ivy Hill SDF"), for approximately $33 million in cash. Ivy Hill SDF currently has approximately $294 million of committed capital invested primarily in first lien loans and to a lesser extent, second lien loans of middle-market companies. IHAM manages Ivy Hill SDF and receives fee income and potential equity distributions in respect of interests that it acquired in Ivy Hill SDF.

Revolving Credit Facility

              On January 22, 2010, we entered into an agreement to amend and restate our senior secured revolving credit facility (the "Revolving Credit Facility"). The amendment and restatement of the Revolving Credit Facility, among other things, increased the size of the facility from $525 million to $690 million (comprised of $615 million in commitments on a stand-alone basis and an additional $75 million in commitments contingent upon the closing of the Allied Acquisition), extended the maturity date to January 22, 2013 and modified pricing. Subject to certain exceptions, pricing under our prior revolving credit facility was based on LIBOR plus 1.00% or on an "alternate base rate" (which was the highest of a prime rate, the federal funds rate plus 0.50%, or one month LIBOR plus 1.00%). Subject to certain exceptions, pricing under the Revolving Credit Facility is based on LIBOR plus an applicable spread of between 2.50% and 4.00% or on the "alternate base rate" plus an applicable

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spread of between 1.50% and 3.00%, in each case based on a pricing grid depending on our credit rating. The effective LIBOR spread under the Revolving Credit Facility on January 22, 2010 was 3.00%. The Revolving Credit Facility is secured by substantially all of our assets (subject to certain exceptions, including investments held by certain of our subsidiaries).

              The Revolving Credit Facility includes an "accordion" feature that allows us, under certain circumstances, to increase the size of the Revolving Credit Facility to a maximum of $897.5 million prior to the closing of the Allied Acquisition, and up to a maximum of $1.05 billion upon the closing of the Allied Acquisition.

Amendment to CP Funding Facility

              On January 22, 2010, we combined our existing $225 million amortizing Ares Capital CP Funding LLC facility (the "CP Funding Facility") with our existing $200 million revolving CP Funding II LLC facility (together, the "CP Funding Facilities"), both with Wachovia Bank, National Association, into a single $400 million revolving securitized facility. In connection with the combination, we entered into an Amended and Restated Purchase and Sale Agreement with Ares Capital CP Funding Holdings LLC, our wholly owned subsidiary ("CP Holdings"), pursuant to which we will sell to CP Holdings certain loans that we have originated or acquired, or will originate or acquire (the "Loans") from time to time, which Loans CP Holdings will subsequently sell to Ares Capital CP Funding LLC, a wholly owned subsidiary of CP Holdings ("Ares Capital CP"). The CP Funding Facility is secured by all of the assets held by Ares Capital CP and the membership interest in CP Holdings.

              The combined CP Funding Facility, among other things, extends the maturity date to January 22, 2013 (with two one-year extension options, subject to mutual consent). Subject to certain exceptions, the interest charged on the CP Funding Facility is based on LIBOR plus an applicable spread of between 2.25% and 3.75% or on a "base rate" (which is the higher of a prime rate, or the federal funds rate plus 0.50%) plus an applicable spread of between 1.25% to 2.75%, in each case, based on a pricing grid depending upon our credit rating. The effective LIBOR spread under the CP Funding Facility on January 22, 2010 was 2.75%.

Other Investment Activity

              As of January 15, 2010, we made $381.8 million of investments (including agreements to fund revolving credit facilities or delayed draw loans) since September 30, 2009. Of these investments, approximately 27% were made in first lien senior secured debt, 62% in senior subordinated debt and 11% in equity/other securities. Of these investments, 26% bear interest at floating rates with a weighted average stated rate of LIBOR plus 11% and 65% bear interest at fixed rates with a weighted average stated rate of 16.6%. As of January 15, 2010, we exited $423.9 million of investments since September 30, 2009. Of these investments, approximately 31% were first lien senior secured debt, 18% were second lien senior secured debt, 48% were senior subordinated debt and 3% were equity securities. Of these investments, 43% bear interest at floating rates with a weighted average stated rate of LIBOR plus 7% and 47% bear interest at fixed rates with a weighted average stated rate of 12%.

              In addition, as of January 21, 2010, we had an investment backlog and pipeline of $137.7 million and $214.9 million, respectively. We expect to syndicate a portion of these investments and commitments to third parties. The consummation of any of the investments in this backlog and pipeline depends upon, among other things: satisfactory completion of our due diligence investigation of the prospective portfolio company, our acceptance of the terms and structure of such investment and the execution and delivery of satisfactory transaction documentation. We cannot assure you that we will make any of these investments or that we will syndicate any portion of our investments and commitments.

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Other Acquisitions

              We believe that the dislocation in the credit markets has created compelling risk adjusted returns in both the primary and secondary markets. Further, the current dislocation and illiquidity in the credit markets has also increased the likelihood of further consolidation in our industry. To that end, over the past 12-18 months we have evaluated (and expect to continue to evaluate in the future) a number of potential strategic acquisition opportunities, including acquisitions of:

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asset portfolios;



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contracts to manage collateralized loan obligation, or CLO, vehicles and other investment vehicles;



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other private and public finance companies or asset managers; and



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selected secondary market assets.

              For example, in June 2009 our portfolio company IHAM completed the acquisition of contracts to sub-manage approximately $770 million of middle market loan assets in three CLO vehicles managed by affiliates of Wells Fargo & Company. IHAM also acquired certain equity interests in these three CLOs. On October 26, 2009, we entered into a definitive agreement to acquire Allied Capital in an all stock transaction valued at $648 million, or approximately $3.47 per Allied Capital share as of October 23, 2009. See "—Allied Acquisition." In addition, on October 30, 2009, we completed our acquisition of Allied Capital's interests in the SL Fund for $165 million in cash and on December 29, 2009, we made an incremental investment in IHAM to facilitate its acquisition of Allied Capital's management rights in respect of, and interests in, Ivy Hill SDF for approximately $33 million in cash. See "—Unitranche Fund Acquisition" and "—Ivy Hill SDF Acquisition."

              We have been and continue to be engaged in discussions with counterparties in respect of various potential strategic acquisition and investment transactions, including potential acquisitions of other finance companies. Some of these transactions could be material to our business and, if consummated, could be difficult to integrate, result in increased leverage or dilution and/or subject us to unexpected liabilities. However, none of these discussions has progressed to the point where the consummation of any such transaction could be deemed to be probable or reasonably certain as of the date of this prospectus. Consummation of any such transaction will be subject to completion of due diligence, finalization of key business and financial terms (including price) and negotiation of final definitive documentation as well as a number of other factors and conditions including, without limitation, the approval of our board of directors (after having determined that such transaction is in the best interest of our stockholders), any required third party consents and, in certain cases, the approval of our stockholders. We cannot predict how quickly the terms of any such transaction could be finalized, if at all. Accordingly, there can be no assurance that definitive documentation for any such transaction would be executed or even if executed, that any such transaction will be consummated. In connection with evaluating potential strategic acquisition and investment transactions, we have, and may in the future, incur significant expenses for the evaluation and due diligence investigation of these potential transactions.

OUR CORPORATE INFORMATION

              Our administrative offices are located at 2000 Avenue of the Stars, 12th Floor, Los Angeles, California 90067, telephone number (310) 201-4200, and our executive offices are located at 280 Park Avenue, 22nd Floor, Building East, New York, New York 10017, telephone number (212) 750-7300.

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OFFERINGS

              We may offer, from time to time, up to $1,000,000,000 of our common stock, preferred stock, debt securities, subscription rights to purchase shares of our common stock or warrants representing rights to purchase shares of our common stock, preferred stock or debt securities, or units comprised of any combination of the foregoing, on terms to be determined at the time of the offering. We will offer our securities at prices and on terms to be set forth in one or more supplements to this prospectus. The offering price per share of our common stock, less any underwriting commissions or discounts, generally will not be less than the net asset value per share of our common stock at the time of an offering. However, we may issue shares of our common stock pursuant to this prospectus at a price per share that is less than our net asset value per share (a) in connection with a rights offering to our existing stockholders, (b) with the prior approval of the majority of our common stockholders or (c) under such other circumstances as the SEC may permit. Any such issuance of shares of our common stock below net asset value may be dilutive to the net asset value of our common stock. See "Risk Factors—Risks Relating to Offerings Pursuant to this Prospectus." As of the date of this registration statement, we had offered $115,069,149 of the $1,000,000,000 of securities covered by this registration statement.

              We may offer our securities directly to one or more purchasers, including existing stockholders in a rights offering, through agents that we designate from time to time or to or through underwriters or dealers. The prospectus supplement relating to each offering will identify any agents or underwriters involved in the sale of our securities, and will set forth any applicable purchase price, fee, commission or discount arrangement between us and our agents or underwriters or among our underwriters or the basis upon which such amount may be calculated. See "Plan of Distribution." We may not sell any of our securities through agents, underwriters or dealers without delivery of a prospectus supplement describing the method and terms of the offering of our securities.

              Set forth below is additional information regarding offerings of our securities:

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FEES AND EXPENSES

              The following table is intended to assist you in understanding the costs and expenses that an investor in our common stock will bear directly or indirectly, based on the assumptions set forth below. We caution you that some of the percentages indicated in the table below are estimates and may vary. Except where the context suggests otherwise, whenever this prospectus contains a reference to fees or expenses paid or to be paid by "you," "us," "the Company" or "Ares Capital," or that "we" will pay fees or expenses, stockholders will indirectly bear such fees or expenses as investors in Ares Capital.

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Example

              The following example demonstrates the projected dollar amount of total cumulative expenses over various periods with respect to a hypothetical investment in our common stock. In calculating the following expense amounts, we have assumed that we would have no additional leverage, that none of our assets are cash or cash equivalents, and that our annual operating expenses would remain at the levels set forth in the table above. Transaction expenses are not included in the following example. In the event that shares to which this prospectus relates are sold to or through underwriters, a corresponding prospectus supplement will restate this example to reflect the applicable sales load.

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              The foregoing table is to assist you in understanding the various costs and expenses that an investor in our common stock will bear directly or indirectly. While the example assumes, as required by the SEC, a 5% annual return, our performance will vary and may result in a return greater or less than 5%. The incentive fee under the investment advisory and management agreement, which, assuming a 5% annual return, would either not be payable or have an insignificant impact on the expense amounts shown above, is not included in the example. If we achieve sufficient returns on our investments, including through the realization of capital gains, to trigger an incentive fee of a material amount, our expenses, and returns to our investors, would be higher. In addition, while the example assumes reinvestment of all dividends and distributions at net asset value, if our board of directors authorizes and we declare a cash dividend, participants in our dividend reinvestment plan who have not otherwise elected to receive cash will receive a number of shares of our common stock, determined by dividing the total dollar amount of the dividend payable to a participant by the market price per share of our common stock at the close of trading on the valuation date for the dividend. See "Dividend Reinvestment Plan" for additional information regarding our dividend reinvestment plan.

              This example and the expenses in the table above should not be considered a representation of our future expenses as actual expenses (including the cost of debt, if any, and other expenses) may be greater or less than those shown.

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SELECTED CONDENSED CONSOLIDATED FINANCIAL DATA OF ARES CAPITAL

              The following selected financial and other data for the years ended December 31, 2008, 2007, 2006 and 2005, and for the period from June 23, 2004 (inception) through December 31, 2004 are derived from our consolidated financial statements, which have been audited by KPMG LLP, an independent registered public accounting firm whose report thereon is included elsewhere in this prospectus. The selected financial and other data for the nine months ended September 30, 2009 and other quarterly financial information is derived from our unaudited financial statements, but in the opinion of management, reflects all adjustments (consisting only of normal recurring adjustments) that are necessary to present fairly the results of such interim periods. Interim results as of and for the nine months ended September 30, 2009 are not necessarily indicative of the results that may be expected for the year ending December 31, 2009. The data should be read in conjunction with our consolidated financial statements and notes thereto and "Management's Discussion and Analysis of Financial Condition and Results of Operations" and "Senior Securities," which are included elsewhere in this prospectus.

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ARES CAPITAL CORPORATION AND SUBSIDIARIES
SELECTED FINANCIAL DATA
As of and For the Nine Months Ended September 30, 2009, As of and For the Years Ended December 31, 2008, 2007, 2006 and 2005 and As of and For the Period June 23, 2004 (inception)
Through December 31, 2004
(dollar amounts in thousands, except per share data and as otherwise indicated)

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SELECTED QUARTERLY DATA (Unaudited)
(dollar amounts in thousands, except per share data)

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UNAUDITED SELECTED PRO FORMA CONDENSED CONSOLIDATED FINANCIAL DATA

              The following tables set forth unaudited pro forma condensed consolidated financial data for Ares Capital and Allied Capital as a consolidated entity. The information as of September 30, 2009 is presented as if the Allied Acquisition had been completed on September 30, 2009 and after giving effect to certain transactions that occurred subsequent to September 30, 2009. The unaudited pro forma condensed consolidated operating data for the nine months ended September 30, 2009 and for the year ended December 31, 2008 are presented as if the Allied Acquisition had been completed January 1, 2008. In the opinion of management, all adjustments necessary to reflect the effect of these transactions have been made. The Allied Acquisition will be accounted for under the acquisition method of accounting as provided by ASC 805-10 (previously Statement of Financial Accounting Standards, or "SFAS," No. 141(R)), Business Combinations.

              The unaudited pro forma condensed consolidated financial data should be read together with the respective historical audited and unaudited consolidated financial statements and financial statement notes of Allied Capital and Ares Capital in this document. The unaudited pro forma condensed consolidated financial data are presented for comparative purposes only and do not necessarily indicate what the future operating results or financial position of Ares Capital will be following completion of the Allied Acquisition. The unaudited pro forma condensed consolidated financial data does not include adjustments to reflect any cost savings or other operational efficiencies that may be realized as a result of the Allied Acquisition of Allied Capital and Ares Capital or any future merger related restructuring or integration expenses.

              We cannot assure you that the Allied Acquisition will be consummated as scheduled, or at all. See "Pending Allied Acquisition" for a description of the terms of the Allied Acquisition and "Risk Factors—Risks Relating to Our Business—We may fail to consummate the Allied Acquisition" for a description of the risks associated with a failure to consummate the Allied Acquisition.

(dollar amounts in thousands, except per share data and as otherwise indicated)