As a young adult, he met well-known movie personalities like Alfred Hitchcock, David Lean, and Doris Day when they visited the family's apartment.

[4] After working in the mail room of Warner Bros. while studying at the University of California, Los Angeles,[5] Canton started working for 20th Century Fox and later had jobs with film director Franklin Schaffner, with producer Jon Peters, and in the 1970s as executive assistant to Mike Medavoy at United Artists.

Successes he was involved in at the time include 1983's National Lampoon's Vacation, Purple Rain, and the Batman and Lethal Weapon film series,[6] but also notorious box office failures like The Bonfire of the Vanities (1990),[7] a picture he described as "the best movie I ever saw" at its first screening.

[9] Warner Bros. let him out of his contract fifteen months early with studio head Bob Daly saying "from our standpoint this was a job that was going to be eliminated.

[12] Described at the time as both "known for enthusiasm, rapid-fire talk, a sleek Italian wardrobe and a youthful style"[5] and "a braggart who was lucky to have become chairman of a studio in the first place",[13] Canton was in those years "one of the most powerful executives in Hollywood".