Middlefield Banc (MBCN) POS AM Prospectus update (post-effective amendment)

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement of Middlefield Banc Corp. on FormS-3 of our report dated March 11, 2014, on Middlefield Banc Corp.’s consolidated financial statements appearing in the Annual Report on Form10-K of Middlefield Banc Corp. for the year ended December 31, 2013, and to the reference to us under the heading “Experts” in the prospectus, which is part of this registration statement.

/s/ S.R. Snodgrass, P.C.

Wexford, Pennsylvania

October 1, 2014