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: August 3, 2015

(Date of earliest event reported)

WhiteHorse Finance, Inc.

(Exact name of registrant as specified in its charter)

(305) 381-6999

(Registrant’s telephone number, including area code)

Not Applicable

(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:

On August 3, 2015, the Company held its annual meeting of stockholders (the “Annual Meeting”). At the Annual Meeting, the Company’s stockholders approved two proposals. The issued and outstanding shares of stock of the Company entitled to vote at the Annual Meeting consisted of 14,982,857 shares of common stock outstanding on the record date, June 8, 2015. The final voting results from the Annual Meeting were as follows:

Proposal 1. To elect two Class III directors of the Company who will each serve for a term of three years or until his successor is duly elected and qualifies.

Proposal 2. To authorize flexibility for the Company, with the approval of the Company’s Board of Directors, to sell shares of the Company’s common stock (during the next 12 months) at a price below the then-current net asset value per share, subject to certain limitations described in the Company’s proxy statement.

Forward-Looking Statements

This Current Report on Form 8-K may contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Statements other than statements of historical facts included in this Current Report on Form 8-K may constitute forward-looking statements and are not guarantees of future performance or results and involve a number of risks and uncertainties. Actual results may differ materially from those in the forward-looking statements as a result of a number of factors, including those described from time to time in filings with the Securities and Exchange Commission. The Company undertakes no duty to update any forward-looking statement made herein. All forward-looking statements speak only as of the date of this Current Report on Form 8-K.

SIGNATURE

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.