Biehn got his start in movies with a bit part in the film version of Grease in 1978. He appears in two scenes, in one which John Travolta's character, Danny, hits Biehn's uncredited character in the stomach while playing basketball. In 1981, he acted out the title role of Douglas Breen, a stalker, in the 1981 film version of Bob Randall's novel The Fan; at the time the film was shot, he was in his mid-20s, whereas the Actress chosen as Breen's victim Sally Ross, Lauren Bacall, was more than 30 years his senior. After a few more films, Biehn played Kyle Reese, a sergeant sent back in time by John Connor to save his mother, Sarah Connor, in the 1984 film The Terminator. He starred in two other films directed by James Cameron: Aliens (as Corporal Hicks) and The Abyss (as Lieutenant Hiram Coffey), and had a small role in Terminator 2: Judgment Day (his briefly reprised role as Reese which was removed from the theatrical release, but restored in the special editions and the director's cut).
Biehn has been married three times. His first wife was Actress Carlene Olson, whom he married on July 11, 1980. They had twin sons, Devon and Taylor (b. 1984) and divorced in 1987. He then married his second wife, Gina Marsh. They had two sons, Caelan Michael (b. April 11, 1992) and Alexander (b. March 19, 2003) and separated in 2008. Biehn is now married to Actress Jennifer Blanc, who co-produced and starred alongside him in The Victim. The couple have one son, Dashiell King Biehn, born March 21, 2015.
In the 2000s, Biehn took acting roles ranging from big budget films such as The Art of War and Clockstoppers, to video games like Command & Conquer: Tiberian Sun, and independent movies, such as Havoc. He also starred in three TV series including the CBS drama The Magnificent Seven (1998–2000), the Tribune Entertainment syndicated TV series Adventure Inc. (2002–2003), and the NBC TV series Hawaii (2004). All three shows were subsequently cancelled because of low ratings. Biehn was considered for a role in James Cameron's science fiction epic film Avatar (2009), but Cameron felt his appearance in the film coupled with that of Sigourney Weaver's would remind people too much of Aliens.
Biehn directed the 2010 film The Blood Bond. In 2011 he wrote, directed and starred in The Victim, which was released in 2011.