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):

July 11, 2023 (July 10, 2023)

RUNWAY GROWTH FINANCE CORP.

(Exact name of registrant as specified in its charter)

205 N. Michigan Ave., Suite 4200

Chicago, Illinois 60601

(Address of principal executive offices and zip code)

Registrant’s telephone number, including area code: (312) 281-6270

Check the appropriate box below if the Form 8-K 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 or Rule 12b-2 of the Securities Exchange Act of 1934. Emerging growth company x

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 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On July 10, 2023, Brian Laibow informed the Board of Directors (the “Board”) of Runway Growth Finance Corp., a Maryland corporation (the “Company”), of his intent to resign as director of the Company, effective upon the appointment by the Board of another nominee by OCM Growth Holdings, LLC (“OCM”) in accordance with the Stockholder Agreement between the Company and OCM, dated December 15, 2016. Mr. Laibow’s decision was not due to any disagreements with the Company relating to the Company’s operations, policies or practices. The Company thanks Mr. Laibow for his service to the Company and wishes him well.

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.