CONFIRMING STATEMENT

This Statement confirms that the undersigned, Stephen A. Drahnak, has
authorized and designated each of Melanie A. Hubler, Kendra J. Milner or
Timothy P. McKee to execute and file on the undersigned's behalf all Forms 3,
4 and 5 (including any amendments thereto) that the undersigned may be
required to file with the U.S. Securities and Exchange Commission as a result
of the undersigned's ownership of or transactions in securities of S&T
Bancorp, Inc. The authority of Melanie A. Hubler, Kendra J. Milner or
Timothy P. McKee under this Statement shall continue until the undersigned is
no longer required to file Forms 3, 4 and 5 with regard to his/her ownership of
or transactions in securities of S&T Bancorp, Inc., unless earlier revoked in
writing. The undersigned acknowledges that Melanie A. Hubler, Kendra J.
Milner or Timothy P. McKee are not assuming any of the undersigned's
responsibilities to comply with Section 16 of the Securities Exchange Act of
1934.



Date: December 28, 2011

/s/ Stephen A. Drahnak