After serving six years, he joined the Detroit Police Department. He then left law enforcement to begin a career in acting. In 1965 Matheson appeared in the Lost in Space episode, The Sky Is Falling in the non-speaking role of the alien Retho and then again in 1967 as IDAK Alpha 12 in the episode Revolt of the Androids. In 1967, he appeared as a guest star in the episode "Deadly Amphibians" on the sci-fi TV show's 4th season Voyage to the Bottom of the Sea.
In 1967, Matheson was cast as william Clark, with Victoria Vetri as Sacajawea in the episode "The Girl Who Walked the West" of the syndicated television series, Death Valley Days, hosted by Robert Taylor. Dick Simmons played Meriwether Lewis; Victor French was cast as Toussaint Charbonneau, Sacajawea's husband.
After working in a number of plays, television episodes and commercials, Matheson was signed to join the cast of the Land of the Giants. He married co-star Deanna Lund in 1970, but they were divorced in the late 1970s. In 1976, he played the role of wealthy industrialist, Cameron Faulker, who married Lesley Williams (Denise Alexander) on General Hospital. His mistress, Peggy Lowell, was played by Lund. The Cameron character was later murdered. In 1984, Matheson had a regular role in Falcon Crest. He played Richard Channing's henchman for a season. He also appeared briefly in Dynasty.
He died on June 29, 2014, in Woodland Hills, Los Angeles from lung cancer, aged 84.
