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 19, 2025

GOLUB CAPITAL BDC, INC.

(Exact name of Registrant as specified in its charter)

Delaware

814-00794

27-2326940

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

200 Park Avenue, 25th Floor, New York, NY 10166

(Address of Principal Executive Offices) (Zip Code)

Registrant’s telephone number, including area code: (212) 750-6060

(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 (see General Instruction A.2. below):

¨	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 communions 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(s)		Name of each exchange on which registered
Common Stock, par value $0.001 per share		GBDC		The Nasdaq Global Select Market

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

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 September 19, 2025, Golub Capital BDC, Inc. (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) by and among the Company, GC Advisors LLC (the “Adviser”), Golub Capital LLC (the “Administrator”), and RBC Capital Markets, LLC, as the underwriter set forth therein, in connection with the issuance and sale of an additional $250.0 million aggregate principal amount of the Company’s 7.050% Notes due 2028 (the “New Notes” and the issuance and sale of the New Notes, the “Offering”). The closing of the Offering is expected to occur on September 26, 2025, subject to customary closing conditions.

The Underwriting Agreement includes customary representations, warranties, and covenants by the Company, the Adviser, and the Administrator. It also provides for customary indemnification by each of the Company, the Adviser, the Administrator, and the underwriter against certain liabilities and customary contribution provisions in respect of those liabilities.

The Offering was made pursuant to the Company’s effective shelf registration statement on Form N-2 (File No. 333-286240) previously filed with the Securities and Exchange Commission (the “SEC”), as supplemented by a preliminary prospectus supplement dated September 19, 2025, a final prospectus supplement dated September 19, 2025, and the pricing term sheet filed with the SEC on September 19, 2025. This Current Report on Form 8-K shall not constitute an offer to sell or a solicitation of an offer to buy any securities, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction.

The foregoing description of the Underwriting Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Underwriting Agreement filed as an exhibit hereto and incorporated by reference herein.

Item 9.01.

Financial Statements and Exhibits.

(d) Exhibits

EXHIBIT NUMBER		DESCRIPTION
1.1		Underwriting Agreement, dated September 19, 2025, by and among Golub Capital BDC, Inc., GC Advisors LLC, Golub Capital LLC, and RBC Capital Markets, LLC, as the underwriter set forth therein.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

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

	Golub Capital BDC, Inc.

Date: September 25, 2025	By:	/s/ Christopher C. Ericson
		Christopher C. Ericson
		Chief Financial Officer and Treasurer

Golub Capital BDC Inc. filed SEC Form 8-K: Entry into a Material Definitive Agreement, Financial Statements and Exhibits