Worthy was born in Detroit, Michigan to a father who worked in the automotive industry. Worthy studied Tae Kwon Do at a young age. He graduated from Southfield Senior High School in 1985 and from the University of Michigan in 1990. Worthy became a stage actor in Detroit, later moving to Chicago, Illinois to develop his theatrical skills. Later, he moved to Los Angeles, California with the goal of acting in film and television.
Worthy had a supporting role in the Star Trek film Star Trek: Insurrection. Worthy also worked on a short-lived 2005 private eye drama on ABC, Eyes. He guest-starred in "The Warrior", an episode of Stargate SG-1, where he made use of his Tae Kwon Do and stunt fighting skills as the Goa'uld Imhotep. He appeared on the 2003–09 re-imagined version of Battlestar Galactica as a Cylon (model Number Four, often referred to as "Simon"). He had a large role on ABC Family's Fallen miniseries.
He played Nathan Jackson on the 1998–99 TV show The Magnificent Seven. Worthy appeared in four episodes of Heroes, playing "Mike", Matt Parkman's partner, an experienced and capable Los Angeles cop. He also had a part in the TV series Supernatural playing the unnamed Alpha Vampire in two episodes of Season 6 and one episode of season 7.