[3][page needed] Raised Catholic, from 1935 to 1953 he attended St. Joseph's School and Campion College in Regina, Saskatchewan, where his acting career began under the direction of the Rev.

[2] Vernon made his screen debut in 1956 as the voice of Big Brother in Michael Anderson's film version of George Orwell's 1984 starring Edmond O'Brien.

He returned to Canada afterwards and gained film experience appearing on the TV series The Adventures of Tugboat Annie and The Last of the Mohicans.

With TV work proving precarious, and the Canadian film industry essentially non-existent at the time, by the end of 1967 Vernon decided to go to the United States to further his acting career.

He also played Mr. Prindle in 1980's Herbie Goes Bananas, Ted Striker's psychiatrist Dr. Stone in 1982's Airplane II: The Sequel, and Sherman Krader in 1987's Ernest Goes to Camp.

In 1979, Vernon played villainous American bigot Jonathon Pritts in New Mexico, who was trying to steal the land from Mexican landowners in the Louis L'Amour story of The Sacketts.

He also appeared in several cult exploitation and action films in the 1980s, most notably Chained Heat and Savage Streets, both starring Linda Blair, and Jungle Warriors, opposite Sybil Danning.

He underplayed his villain image (playing a character called "Mr. Big") in the 1988 Blaxploitation spoof I'm Gonna Git You Sucka: a character thinks Vernon should be "above exploitation films" and Vernon replies that many famous actors have done exploitation films, listing Jamie Lee Curtis, Angie Dickinson, and Shelley Winters as examples.

He played Sergeant Curt Mooney in Killer Klowns from Outer Space and was a lead in the short-lived 1990s series Acapulco H.E.A.T.

Vernon guest starred as the grouchy principal Dinkler in "Brad to Worse", an episode of Duckman on USA Network.