This Statement confirms that the undersigned, David P. Ruddock, has authorized
and designated each of Robert E. Rout, Wendy S. Bell 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 Robert E. Rout, Wendy S. Bell 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 Robert E. Rout, Wendy S. Bell 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.


/s/ David P. Ruddock

