GLADSTONE CAPITAL CORP (0001143513) (Filer)

Dated: October 26, 2026

GLADSTONE CAPITAL CORPORATION

/s/ Nicole Schaltenbrand

Nicole Schaltenbrand

Chief Financial Officer & Treasurer

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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): October 26, 2026 (October 22, 2026)

Gladstone Capital Corporation

(Exact name of registrant as specified in its charter)

Maryland

814-00237

54-2040781

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

1521 Westbranch Drive, Suite 100

McLean, Virginia

22102

(Address of principal executive offices)

(Zip Code)

(703) 287-5800

(Registrant’s telephone number, including area code)

(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))

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

Title of each class

Trading

symbol

Name of each exchange

on which registered

Common Stock, $0.001 par value per share

GLAD

The Nasdaq Stock Market LLC

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 5.02

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

On October 22, 2026, Walter H. Wilkinson Jr. notified Gladstone Capital Corporation (the “Company”) that he is resigning from the Company’s Board of Directors, effective immediately. Mr. Wilkinson has served as a director since 2014 and as Lead Independent Director since 2024. The Board has elected George “Chip” Stelljes, III to succeed Mr. Wilkinson as Lead Independent Director, effective October 26, 2026. Following Mr. Wilkinson’s resignation, the Board fixed the number of directors at seven, effective October 26, 2026.

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.