Sixth Street Specialty Lending, Inc. Reports First Quarter 2021 Earnings Results; Declares a Second Quarter Base Dividend Per Share of $0.41 and a First Quarter Supplemental Dividend Per Share of $0.06

NEW YORK–(BUSINESS WIRE)–Sixth Street Specialty Lending, Inc. (NYSE: TSLX, or the “Company”) today reported financial results for the first quarter ended March 31, 2021. Please view a printable version of the 2021 First Quarter Results.

Conference Call Information:

A conference call to discuss the Company’s financial results will be held live at 8:30 a.m. Eastern Time on May 5, 2021. Please visit TSLX’s webcast link located on the Events & Presentations page of the Investor Resources section of TSLX’s website http://www.sixthstreetspecialtylending.com for a slide presentation that complements the Earnings Conference Call. Please visit the website to test your connection before the webcast.

Participants are also invited to access the conference call by dialing one of the following numbers:

Domestic: (877) 359-9508

International: +1 (253) 237-1122

Conference ID: 9277414

All callers will need to enter the Conference ID followed by the # sign and reference “Sixth Street Specialty Lending” once connected with the operator. All callers are asked to dial in 10-15 minutes prior to the call so that name and company information can be collected.

Replay Information:

An archived replay will be available from approximately 12:00 p.m. Eastern Time on May 5 through May 12 via a webcast link located on the Investor Resources section of TSLX’s website, and via the dial-in numbers listed below:

Domestic: (855) 859-2056

International: +1 (404) 537-3406

Conference ID: 9277414

Please direct any questions regarding the conference call to TSLX Investor Relations, IRTSLX@sixthstreet.com.

About Sixth Street Specialty Lending

Sixth Street Specialty Lending is a specialty finance company focused on lending to middle-market companies. The Company seeks to generate current income primarily in U.S.-domiciled middle-market companies through direct originations of senior secured loans and, to a lesser extent, originations of mezzanine loans and investments in corporate bonds and equity securities. The Company has elected to be regulated as a business development company, or a BDC, under the Investment Company Act of 1940 and the rules and regulations promulgated thereunder. The Company is externally managed by Sixth Street Specialty Lending Advisers, LLC, an affiliate of Sixth Street and a Securities and Exchange Commission (“SEC”) registered investment adviser. The Company leverages the deep investment, sector, and operating resources of Sixth Street, a global investment firm with over $50 billion of assets under management and committed capital. For more information, visit the Company’s website at www.sixthstreetspecialtylending.com.

About Sixth Street

Sixth Street is a global investment firm with over $50 billion in assets under management and committed capital. We operate nine diversified, collaborative investment platforms: TAO, Growth, Specialty Lending, Fundamental Strategies, Infrastructure, Opportunities, Insurance, Agriculture, and Credit Market Strategies. Our long-term oriented, highly flexible capital base and “One Team” cultural philosophy allow us to invest thematically across sectors, geographies, and asset classes. Founded in 2009, Sixth Street has more than 320 team members including over 145 investment professionals in nine locations around the world. For more information about Sixth Street, visit www.sixthstreet.com.

Forward-Looking Statements

Statements included herein may constitute “forward-looking statements,” which relate to future events or the Company’s future performance or financial condition, including expectations with respect to the Company’s portfolio companies. These statements are not guarantees of future performance, conditions or results and involve a number of risks and uncertainties. Actual results may differ materially from those in the forward-looking statements as a result of a number of factors, including those described from time to time in the Company’s filings with the Securities and Exchange Commission. The Company assumes no obligation to update any such forward-looking statements.

Contacts

Investors:

Lucy Lu, 212–601-4753

Sixth Street Specialty Lending

IRTSLX@sixthstreet.com

Media:

Patrick Clifford, 617-793-2004

Sixth Street

PClifford@sixthstreet.com