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): April 19, 2016

BUSINESS FIRST BANCSHARES, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (225) 248-7600

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):

On April 19, 2016, Business First Bancshares, Inc. (the “Company”) issued a press release announcing (i) the declaration of a cash dividend in the amount of $0.05 per share, which will be paid on May 16, 2016, or as soon as practicable thereafter, to shareholders of record at the close of business on April 29, 2016, and (ii) its earnings for the quarter ended March 31, 2016. A copy of the press release (the “Press Release”) is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference herein.

On April 20, 2016, the Company also issued a letter to its shareholders discussing (i) its results of operations for the quarter ended March 31, 2016, and (ii) the declaration of the cash dividend. A copy of the shareholder letter is filed as Exhibit 99.2 to this Form 8-K and is incorporated herein by reference.

The information contained in this Current Report on Form 8-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

The Securities and Exchange Commission encourages registrants to disclose forward-looking information so that investors can better understand the future prospects of a registrant and make informed investment decisions. This Current Report on Form 8-K and exhibits may contain these types of statements, which are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, and which involve risks, uncertainties and reflect the Company’s judgment as of the date of this Current Report on Form 8-K. Forward-looking statements may relate to, among other things, operating results and are indicated by words or phrases such as “expects,” “should,” “will,” and similar words or phrases. These statements are subject to inherent uncertainties and risks that could cause actual results to differ materially from those anticipated at the date of this Current Report on Form 8-K. The Company disclaims any obligation to, and will not, update any forward-looking statements to reflect events or circumstances after the date hereof. Investors are cautioned not to rely unduly on forward-looking statements when evaluating the information presented herein.

The following exhibits are filed herewith.

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, thereunto duly authorized.

Dated: April 22, 2016

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