Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the Registration Statement on Form S-3 (No. 333-34148) of First National Corporation and subsidiaries of our report, dated March 25, 2013, relating to our audit of the consolidated financial statements, which appear in the Annual Report on Form 10-K of First National Corporation and subsidiaries for the year ended December 31, 2012.

Winchester, Virginia

March 25, 2013