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): September 15, 2025

FS Specialty Lending Fund

(Exact name of Registrant as specified in its charter)

Delaware

(State or other jurisdiction

of incorporation)

814-00841

(Commission

File Number)

27-6822130

(I.R.S. Employer

Identification No.)

201 Rouse Boulevard

Philadelphia, Pennsylvania

(Address of principal executive offices)

19112

(Zip Code)

Registrant’s telephone number, including area code: (215) 495-1150

None

(Former name or former address, if changed since last report)

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))

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 8.01.

Other Events.

FS Specialty Lending Fund (the “Company”) is filing this Current Report on Form 8-K for the purpose of providing its shareholders with a letter recommending that they reject an unsolicited mini-tender offer received from a third party. This letter will be mailed to registered shareholders of the Company. A copy of the letter is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Item 9.01.

Financial Statements and Exhibits.

99.1	Letter to Shareholders, dated September 15, 2025

SIGNATURE

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

		FS Specialty Lending Fund

Date:	September 15, 2025	By:	/s/ Stephen S. Sypherd
			Stephen S. Sypherd
			General Counsel

FS Specialty Lending Fund 8-K