Mark was born on 25 September 1951 in Oakland, CA. The middle child of William and Suzanne Hamill, he has six siblings: Terry, Jan, Jeanie, William Jr, Kim, and Patrick. His father being a captain in the United States Navy, Mark grew up in a variety of places, including California, Virginia, New York City, and Japan. After he graduated from Yokohama HS in 1969, the Hamills moved back to California, where Mark entered Los Angeles City College as a Theatre Arts major.
Mark's professional acting debut was on the original Bill Cosby Show, in 1971. He played an ongoing role on the soap opera General Hospital, and was a co-star in The Texas Wheelers, the first comedy show not to use a 'laugh track'. While he did a voice-over in the animated movie Wizards, (his character looks like him), his film debut was in Star Wars, 1977. He was in a car accident; specific parts of the wampa scene in The Empire Strikes Back, 1980, were written to explain the facial changes.
Mark married Marilou York in 1978. They have three children: Nathan, born 25 June 1979; Griffin, born 4 March 1983; Chelsea, born 27 July 1988. Their main residence is in Malibu, California.
After Return of the Jedi, 1983, Mark concentrated on theatre, and appeared in several Broadway plays, including The Elephant Man, and Amadeus. His most challenging role was the one he originated, that of Tony Hart in Harrigan 'n Hart. He sang and danced in that role, and garnered a Drama Desk nomination for Best Actor in a Musical. He also did several off- Broadway plays.
Returning to film in 1989, Mark has also made several guest appearances on television shows. Two favourites with fans are Just Shoot Me! and The Simpsons. Using his talent for disguising his voice, Mark is much in demand as a voice-over actor Watch Robot Chicken, or Super Robot Monkey Team Hyperforce to hear how versatile he is!
Mark has done several projects in the computer games field, as well. Most notable is as Colonel Christopher Blair in Wing Commander III and IV, and Wing Commander:Prophecy.
The Black Pearl, a five-part graphic novel Mark co-wrote with Eric Johnson, was released on 18 September 1996. It has been adapted to a screenplay. Look for more information on this project in the future!
Mark produced and starred in ComicBook: The Movie, a homage to collectors everywhere. A good bit of this was filmed at the San Diego ComicCon in 2001.
He made a rare convention appearance, at Star Wars Celebration Europe Friday and Saturday, 13th - 14th July 2007 signing autographs. After a one hour talk session with Warwick Davis on the Friday, he participated in the Opening Ceremonies for Celebration Europe.