Bob St. Clair is a former San Francisco American football player known for fine play and eating raw beef. Because of his eccentricities, his teammates nicknamed him "The Geek."

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 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 season 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.

St. Clair also served as mayor of Daly City, California from 1958 to 1961 and a county supervisor for San Mateo County from 1966 to 1974.