Exhibit 21

SUBSIDIARIES OF THE REGISTRANT

S&T Bancorp, Inc., a Pennsylvania corporation, is a financial holding company. The table below sets forth all of our subsidiaries, except certain inactive subsidiaries, as to state or jurisdiction of organization. 

Subsidiary			State or Jurisdiction of Organization
S&T Bank			Pennsylvania
9th Street Holdings, Inc.			Delaware
S&T Bancholdings, Inc.			Delaware
S&T Insurance Group, LLC			Pennsylvania
S&T Professional Resources Group, LLC			Pennsylvania
S&T-Evergreen Insurance, LLC (sold 1/1/2018)			Pennsylvania
S&T Settlement Services, LLC			Pennsylvania
Stewart Capital Advisors, LLC			Pennsylvania
STBA Capital Trust I			Delaware
Commonwealth Trust Credit Life Insurance Company			Arizona
DNB Capital Trust I			Delaware
DNB Capital Trust II			Delaware
DN Acquisition Company, Inc.			Pennsylvania