Oaktree Specialty Lending : Q1 2021 Investor Presentation

Investor Presentation

First Quarter 2021

Nasdaq: OCSL

Forward Looking Statements & Legal Disclosures

Some of the statements in this presentation constitute forward-looking statements because they relate to future events or our future performance or financial condition. The forward-looking statements contained in this presentation may include statements as to: our future operating results and distribution projections; the ability of Oaktree Fund Advisors, LLC ("Oaktree") to reposition our portfolio and to implement Oaktree's future plans with respect to our business; the ability of Oaktree and its affiliates to attract and retain highly talented professionals; our business prospects and the prospects of our portfolio companies; the impact of the investments that we expect to make; the ability of our portfolio companies to achieve their objectives; our expected financings and investments and additional leverage we may seek to incur in the future; the adequacy of our cash resources and working capital; the timing of cash flows, if any, from the operations of our portfolio companies; and the cost or potential outcome of any litigation to which we may be a party. In addition, words such as "anticipate," "believe," "expect," "seek," "plan," "should," "estimate," "project" and "intend" indicate forward-looking statements, although not all forward-looking statements include these words. The forward-looking statements contained in this presentation involve risks and uncertainties. Our actual results could differ materially from those implied or expressed in the forward-looking statements for any reason, including the factors set forth in "Risk Factors" and elsewhere in our annual report on Form 10-K for the fiscal year ended September 30, 2020. Other factors that could cause actual results to differ materially include: changes or potential disruptions in our operations, the economy, financial markets or political environment; risks associated with possible disruption in our operations or the economy generally due to terrorism, natural disasters or the COVID-19 pandemic; future changes in laws or regulations (including the interpretation of these laws and regulations by regulatory authorities) and conditions in our operating areas, particularly with respect to business development companies or regulated investment companies; general considerations associated with the COVID-19 pandemic; the ability of the parties to consummate the two-step merger (the "Mergers") of Oaktree Strategic Income

Corporation ("OCSI") with and into OCSL on the expected timeline, or at all; the ability to realize the anticipated benefits of the Mergers; the effects of disruption on our business from the proposed Mergers; the combined company's plans, expectations, objectives and intentions, as a result of the Mergers; any potential termination of the Merger Agreement; the actions of our stockholders or the stockholders of OCSI with respect to the proposals submitted for their approval in connection with the Mergers; and other considerations that may be disclosed from time to time in our publicly disseminated documents and filings.

We have based the forward-looking statements included in this presentation on information available to us on the date of this presentation, and we assume no obligation to update any such forward-looking statements. Although we undertake no obligation to revise or update any forward-looking statements, whether as a result of new information, future events or otherwise, you are advised to consult any additional disclosures that we may make directly to you or through reports that we in the future may file with the SEC, including annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K.

Additional Information and Where to Find It

This communication relates to the Mergers, along with related proposals for which stockholder approval is being sought (collectively, the "Proposals"). In connection with the Proposals, each of OCSL and

OCSI has filed relevant materials with the SEC, including a registration statement on Form N-14, which includes a joint proxy statement of OCSL and OCSI and a prospectus of OCSL (the "Joint Proxy Statement"). The Joint Proxy Statement was mailed to stockholders of OCSL and OCSI on or about January 21, 2021. This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended. STOCKHOLDERS OF OCSL AND OCSI ARE URGED TO READ ALL RELEVANT DOCUMENTS FILED WITH THE SEC, INCLUDING THE JOINT PROXY STATEMENT, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT OCSL, OCSI, THE

MERGERS AND RELATED MATTERS. Investors and security holders are able to obtain the documents filed with the SEC free of charge at the SEC's website,http://www.sec.govor, for documents filed by OCSL, from OCSL's website athttp://www.oaktreespecialtylending.com, and, for documents filed by OCSI, from OCSI's website at http://www.oaktreestrategicincome.com.

Participants in the Solicitation

OCSL and OCSI and their respective directors, certain of their respective executive officers and certain other members of management and employees of Oaktree Fund Advisors, LLC and its affiliates, may be deemed to be participants in the solicitation of proxies from the stockholders of OCSL and OCSI in connection with the Proposals. Information about the directors and executive officers of OCSL and

OCSI is set forth in the Joint Proxy Statement. Information regarding the persons who may, under the rules of the SEC, be considered participants in the solicitation of the OCSL and OCSI stockholders in connection with the Mergers is contained in the Joint Proxy Statement and other relevant materials filed with the SEC. These documents may be obtained free of charge from the sources indicated above.

No Offer or Solicitation

This presentation is not, and under no circumstances is it to be construed as, a prospectus or an advertisement and the communication of this presentation is not, and under no circumstances is it to be construed as, an offer to sell or a solicitation of an offer to purchase any securities in OCSI, OCSL or in any fund or other investment vehicle managed by Oaktree or any of its affiliates.

Unless otherwise indicated, data provided herein are dated as of December 31, 2020.

Forward Looking Statements & Legal Disclosures (continued)

Calculation of Assets Under Management

References to total "assets under management" or "AUM" represent assets managed by Oaktree and a proportionate amount of the AUM reported by DoubleLine Capital LP ("DoubleLine Capital"), in which Oaktree owns a 20% minority interest. Oaktree's methodology for calculating AUM includes (i) the net asset value ("NAV") of assets managed directly by Oaktree, (ii) the leverage on which management fees are charged, (iii) undrawn capital that Oaktree is entitled to call from investors in Oaktree funds pursuant to their capital commitments, (iv) for collateralized loan obligation vehicles ("CLOs"), the aggregate par value of collateral assets and principal cash, (v) for publicly-traded business development companies, gross assets (including assets acquired with leverage), net of cash, and (vi) Oaktree's pro rata portion (20%) of the AUM reported by DoubleLine Capital. This calculation of AUM is not based on the definitions of AUM that may be set forth in agreements governing the investment funds, vehicles or accounts managed and is not calculated pursuant to regulatory definitions.

Managed by Oaktree: A Leading Global Alternative Asset Manager

• • Founded in 1995, Oaktree is a leading global investment management firm focused on credit investing

  Investment Areas (by AUM)3

  ($ in billions)

• • Assets under management of $148 billion1 in contrarian, value-oriented, risk-controlled investment strategies across a variety of asset classes

  CREDIT $81.5

  PRIVATE EQUITY $15.1

• • Manages assets for a wide variety of clients including many of the most significant investors in the world

REAL ASSETS $15.2

LISTED EQUITIES $8.9

Global Footprint2

Historical Assets Under Management1

As of December 31, 2020

($ in billions)

$160

$148

$140

$120

$100

$80

$60

$40

$20 $

1995

2000

2005

2010

2015

Dec. 2020

• 1 Includes Oaktree's proportionate amount of DoubleLine Capital AUM resulting from its 20% minority interest therein. See Forward Looking Statements & Legal Disclosures section for important information regarding Oaktree's calculation methodology for assets under management.

• 2 Includes offices of affiliates of Oaktree-managed funds in Amsterdam, Luxembourg and Dublin. Oaktree is headquartered in Los Angeles.

• 3 Excludes amount of DoubleLine Capital AUM.