After school, he worked as a male model with moderate success in the advertising field, then came to the attention of MGM and later Universal-International Studios, which put him under contract in 1952.
Although he appeared in films, such as Bonzo Goes to College, Mississippi Gambler, Seven Angry Men, Sincerely Yours, I Was A Teenage Werewolf, The Last Frontier, and Man From the Alamo, Williams' parts were relatively small and it looked like his hopes of becoming a leading man were in vain.
By the time Disney found him, Williams was almost ready to give up his acting career. Luckily for Williams, he auditioned for the role of Zorro, and to his astonishment, he found himself the star of a network series.
After Zorro finished he continued acting, eventually landing another of his most famous roles as Professor John Robinson in the 1968 TV series, Lost In Space.
- Guy was an accomplished fencer.
- He died in 1989 while living in Buenos Aires, Argentina. Investigators and Medical people found him deceased wearing his Zorro mask.