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): January 27, 2016

Farmers National Banc Corp.

(Exact name of registrant as specified in its charter)

(330) 533-3341

(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:

On January 27, 2016, Farmers National Banc Corp. (the “Company”) announced earnings for the quarter and year ended December 31, 2015. A copy of the press release and certain financial information for those periods is attached as Exhibit 99.1 hereto and incorporated by reference herein.

The press release is furnished herein, as part of this Item 2.02, as Exhibit 99.1. Pursuant to General Instruction B.2 of Current Report on Form 8-K, the information in this Item 2.02 and Exhibit 99.1 is being furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section. Furthermore, the information in this Item 2.02 and Exhibit 99.1 shall not be deemed to be incorporated by reference into the filings of the Company under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as may be expressly set forth by specific reference in such filing.

Pursuant to General Instruction B.2 of Current Report on Form 8-K, the information in this Item 2.02 and Exhibit 99.1 is being furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section. Furthermore, the information in this Item 2.02 and Exhibit 99.1 shall not be deemed to be incorporated by reference into the filings of the Company under the Securities Act of 1933, as amended (the “Securities Act”).

On January 29, 2016, the Company first mailed a letter to shareholders regarding its fourth quarter and annual results, a copy of which is attached hereto as Exhibit 99.2.

The shareholder letter is furnished herein, as part of this Item 7.01, as Exhibit 99.2. Pursuant to General Instruction B.2 of Current Report on Form 8-K, the information in this Item 7.01 and Exhibit 99.2 shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section. Furthermore, the information in this Item 7.01 and Exhibit 99.2 shall not be deemed to be incorporated by reference into the filings of the Company under the Securities Act, except as may be expressly set forth by specific reference in such filing.

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.

Date: January 29, 2016