UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): February 5, 2021

Sixth Street Specialty Lending, Inc.

(Exact name of registrant as specified in charter)

Registrant’s telephone number, including area code: (469) 621-3001

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐    Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Item 1.01 – Entry into a Material Definitive Agreement

On February 5, 2021, Sixth Street Specialty Lending, Inc. (the “Company”) entered into a tenth amendment to the Company’s second amended and restated senior secured revolving credit facility, dated February 27, 2014 (as amended, the “Revolving Credit Facility”), which, among other changes, (a) increases the aggregate commitments under the Revolving Credit Facility from $1.335 billion to $1.485 billion, (b) extends the termination of the revolving period on $1.390 billion of commitments from January 31, 2024 to February 4, 2025 and the stated maturity date from January 31, 2025 to February 4, 2026 and (c) increases the accordion feature, which allows the Company, under certain circumstances, to increase the size of the Revolving Credit Facility, from a maximum of $1.75 billion to a maximum of $2.0 billion.

The foregoing description is only a summary of certain of the provisions of the Revolving Credit Facility and is qualified in its entirety by the underlying agreement, which will be filed as an exhibit to the Company’s next Annual Report on Form 10-K.

Item 2.03 – Creation of a Direct Financial Obligation

The information set forth under Item 1.01 above is incorporated by reference into this Item 2.03.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.