Tim Thomerson was born in Coronado, California. He was brought up in both Hawaii and in San Diego. Following a stint in the Army National Guard, where he served as a cook in a tank company with actor Brion James, Thomerson chose to become an actor while taking a job as a set builder and prop man at San Diego's Old Globe Theatre, famous for its Shakespearean productions.
Thomerson entered the world of stand-up comedy in the 1970s. In Los Angeles, he became a regular at the Comedy Store and the Improv and made numerous appearances on television variety shows and in Las Vegas.
One of Thomerson's early acting breaks came from director Robert Altman who, after seeing Thomerson's stand-up act, cast him in the film A Wedding. Thomerson first came to prominence in the short-lived comedy science-fiction TV series, Quark in 1977–78, as Gene/Jean, a character of dual gender who randomly switched between the two.
Feature film actor
Thomerson began a long career in television and film starting in the mid-1970s, starting with roles such as the criminal psychologist Jerry Moriarity in the slasher film, Fade to Black (1980) before moving on to starring roles such as the time-traveling future cop Jack Deth in the 1985 low-budget science-fiction film, Trancers, his most famous role.
When Charles Band started Full Moon Features in the late 1980s, one of his first projects was the sequel Trancers II (1991), in which he reunited Thomerson with much of the cast from the first film. Thomerson would later appear in each of the sequels, except for Trancers 6.
Another notable film role was that of Brick Bardo in Dollman (1991), a Dirty Harry-like alien cop who is only 13 inches (33 cm) tall; the character also appeared briefly in Bad Channels and more substantially in Dollman vs. Demonic Toys
In the 1990s, he was a series regular on the TV police drama, Sirens, followed by a regular, co-starring role on the series, Land's End.