Steuben Trust Company was originally organized in 1902 as the Bank of Steuben. The first office was in the former Babcock State Building at 74 Main Street in Hornell. In 1914 the bank built its Main Office located at 82 Main Street in Hornell, which the bank called home for 85 years. The name of the bank was changed to Steuben Trust Company in 1920 when it began offering trust services.
In 1959 Steuben Trust built an office on Seneca Street in Hornell, followed 10 years later, in 1969, by the Arkport office. It wasn't again until 1988 that Steuben Trust made its next expansion, which was the Alfred office, followed in 1991 by the Canaseraga office.
In 1994, Steuben Trust entered the Wellsville market and built a permanent office there.
Steuben Trust acquired five Key Bank offices in Andover, Belmont, Bolivar, North Hornell, and Whitesville in December 1996.
In the summer of 1999 Steuben Trust completed construction on its current headquarters located at One Steuben Square in downtown Hornell.
Steuben Trust Company constructed a new office in the Bath Plaza which opened in December 2002. The full-service office features a drive-up ATM, drive-up lane, customer service and loan offices.
In September 2006 Steuben Trust opened a new full-service office in Geneseo to include a walk-up ATM, teller line, customer service and loan office. A new ATM Kiosk was also built and opened in the Wellsville area.
In 2007 Steuben Trust closed its North Hornell office and opened a full service office in Henrietta.
In February 2009 Steuben Trust and Canisteo Savings and Loan Association merged to create a new office for Steuben Trust Company in Canisteo.
In May 2012 STC constructed a new office in Warsaw. The full-service office features a drive-up ATM, drive-up teller lane, customer service and loan offices.