He met actress Shelley Plimpton in the Broadway musical Hair. By then, the actress was married to actor Steve Curry but had separated. The two became romantically involved after their first meeting. Later, after Kaith left the show and went to California, he was informed that Shelley was pregnant but had reunited with her husband Steve. Shelley gave birth to her daughter Martha Plimpton whom Keith met when she was 4 years old after Shelley divorced Steve.
After the united with his daughter, Keith said of Shelley “She did a hell of a job raising Martha. I was not there. I was a very young man, absolutely terrified. She just took that in, and then she welcomed me into Martha’s life when I was ready.” On February 6, 1982, Keith married Sandra Will. The couple welcomed their first child, Cade Richmond Carradine on July 19, 1982) and their second child Sorel Johannah Carradine on June 18, 1985).
Keith and Sandra separated in 1993 and Sadra filed for a divorce in 1999. After her divorce from Keith, she became romantically involved with Anthony Pellicano. Keith then married actress Hayley DuMond on November 18, 2006, in Turin, Italy. The two first met in 1997 when they co-starred in the Burt Reynolds film The Hunter’s Moon
