Investar Holding (ISTR) 8-K Investar Holding Corporation Announces Commencement of Subordinated Notes and Common Stock Offerings

Exhibit 23.1

Consent of Independent Auditor

We consent to the incorporation by reference in the Prospectus Supplement to the Registration Statement (No. 333-215238) on Form S-3 of Investar Holding Corporation of our report dated February 17, 2017, relating to the consolidated financial statements of Citizens Bancshares, Inc., appearing in this Current Report on Form 8-K.

We also consent to the reference of our firm under the heading “Experts” in such Prospectus Supplement.

/s/ Hannis T. Bourgeois, LLP

Baton Rouge, Louisiana

March 15, 2017