Frederick Robert Williamson, also known as "the Hammer", is an American actor and former professional football defensive back who played mainly in the American Football League (AFL) during the 1960s. Williamson has had a busy film career, starring as Tommy Gibbs in the 1973 crime drama film Black Caesar and its sequel Hell Up in Harlem. Williamson also had roles in other 1970s blaxploitation films such as Hammer (1972), That Man Bolt (1973) and Three the Hard Way (1974).

Black Caesar is a 1973 American blaxploitation crime drama film written and directed by Larry Cohen and starring Fred Williamson, Gloria Hendry and Julius Harris. It features a musical score by James Brown, his first experience with writing music for film. A sequel titled Hell Up in Harlem was released in late 1973.