Johnson began his career acting at the age of nine, when his parents enrolled him in Stage Polaris, a theater company in Edmonton.

A few years later, he played the title role in the television revival of Flash Gordon that debuted on Sci Fi in August 2007; the series was cancelled after one season.

[3] He also portrayed Luke Callahan in the Canadian police drama Rookie Blue and inmate Cal Sweeney, a bank robber, in the Fox series Alcatraz.

His father, Fred, managed a binding corporation, and his mother, Jane, is a librarian, massage therapist, and music teacher.

[8][9] In 2004, Johnson married writer-producer Adria Budd, whom he met on the set of Smallville, as she was Annette O'Toole's and John Glover's personal assistant.