William Fichtner married Betsy Aidem (an actress; divorced, 1996); and married Kymberly Kalil (an actress), July 25, and has a child.
- William starred in a show named MDs, where he played a character named Bruce Kellerman. Paul Kellerman is a man who worked with Mahone, William's character.
- William met Peter Stormare prior to show: 7 years in 1998 in Armageddon.
- William met John Heard 1 year prior to the show in The Chumscrubber.