Matheson was born on December 31, 1947 in Glendale, California, as Timothy Lewis Matthieson. In his adult life, he became an actor and director, his name being featured in many works, including Van Wilder: Party Liaison, Animal House, and Magnum Force. In his personal life, he had two failed marriages with Jennifer Leak and Megan Murphy Matheson, the latter of whom was the mother of his three children.