William Barclay Foster (1779–1855) was the father of Stephen Foster and a notable businessman in his time. He was one of the most prosperous merchants of Pittsburgh, Pennsylvania. He was a Pennsylvania state legislator and served three terms. He was also elected mayor of Allegheny City twice in his lifetime. He has been identified as a "patriot", a "lover of home" and an "outstanding servant to his community, state and government".
- Occupation
- politician, merchant
- Position held
- Mayor of Allegheny, Pennsylvania, member of the Pennsylvania House of Representatives
- Citizenship
- United States
- Born
- September 7, 1779
