St. Clair holds the distinction of being one of the few players in history to have spent almost his entire playing career in the same city, playing in the same stadium. Bob St. Clair attended San Francisco's Polytechnic High School (located across the street from the stadium) and the University of San Francisco, and was part of USF's undefeated 1951 team. After USF dropped football, St. Clair finished his college career at the University of Tulsa. He was then drafted by the San Francisco 49ers in 1953 and played his entire professional career in San Francisco until his retirement prior to the 1964 season.
In 2001, as a tribute for playing a total of 17 seasons and 189 home games at Kezar Stadium, the city of San Francisco renamed the stadium's field in honor of St. Clair. He was elected to the Pro Football Hall of Fame in 1990.