Ashmore won the Los Angeles Drama Critics Circle Award for Featured Performance in 2005. In 2009, he was nominated for Best Actor by the 168 Hour Film Project, a Christian film festival, for the short Stealing Home.
Ashmore appeared in the 1980 hit comedy film Airplane!, Airplane II: The Sequel and films such as Gable and Lombard (1976), Invisible Strangler (1978), Parts: The Clonus Horror (1979), Monster in the Closet (1986) and Extracted (2012). In 1981, he appeared on both Days of Our Lives as a hit man out to kill Julie Williams and General Hospital as Monica Quartermaine's private investigator. He also had a supporting role in the 2012 independent thriller Extracted. He made guest appearances on various television shows including Happy Days, The Bob Newhart Show, Battlestar Galactica, Touched by an Angel, The West Wing and the current version of Hawaii Five-O. In 2010, he had a recurring role in season 4 of The Guild. He voiced Leone "Leo" Galante in the 2010 video game Mafia II, and its sequel Mafia III. He also voiced Austin Buckell in the 2013 video game Dead Space 3.
He is perhaps best known for his role as "Martin" in the 1983 NBC miniseries V and its 1984 sequel V: The Final Battle. He reprised his role in the pilot episode of V: The Series but was killed off by the end of the episode. He returned later on in V: The Series as Philip, Martin's twin brother.
Ashmore won the Los Angeles Drama Critics Circle Award for Featured Performance in 2005. In 2009, he was nominated for Best Actor by the 168 Hour Film Project, a Christian film festival, for the short Stealing Home.
