John S. Herron (November 7, 1872 – September 13, 1947), served as the 48th Mayor of Pittsburgh from 1933 to 1934.
Born in Oswego, New York, Herron came to Pittsburgh as a blue-collar worker and quickly entered leadership as President of the Bricklayers Union.
During his term, the city adopted the repeal of the commonwealth's "Sunday Blue Laws" prohibiting business and sports for 24 hours.
The repeal of the Blue Laws made it possible for the future Pittsburgh Steelers to join the National Football League.
To date, Herron holds the distinction of having been the last Republican mayor of the City of Pittsburgh.