Patricia is the daughter of Jerry Tallman, a radio entertainer. She is a 1975 graduate of Glenbard West High School in Glen Ellyn, Illinois, and received a bachelor of fine arts (BFA) degree from Carnegie Mellon University's Theater Arts Program.
In television, Tallman worked on the soap opera, Generations. Later, she had guest-starring roles on Tales from the Darkside, and the science fiction shows Star Trek: The Next Generation, Star Trek: Deep Space Nine and Star Trek: Voyager. As an actress and stunt performer, she worked on 50 episodes across the Star Trek franchise. Tallman played Lyta Alexander in the Babylon 5 series pilot, recurring in seasons two and three, and starring in seasons four and five. Tallman collaborated with fellow Carnegie Mellon alumnus George A. Romero on several films, including Knightriders, Monkey Shines, and Creepshow 2 (in which Tallman performed stunts).
In 1990, Tallman starred as Barbara in the Tom Savini-directed remake of the 1968 film Night of the Living Dead. In 1992, she played the Possessed Witch under heavy make-up in the cult classic Army of Darkness, as well as the Witch in the modern day scenes.
In 1993, Tallman's most notable stunt work came as stunt double for Laura Dern throughout Steven Spielberg's Jurassic Park. In addition, she served as stunt double for Laurel Holloman, who portrayed vampire hunter Justine Cooper in the series Angel, a photo of Tallman was also used as the photo of Justine Cooper's dead twin sister. In a 2001 episode of the TV series Sheena she guest starred as the villain Caroline Dula.
Tallman's recent acting credits include the psychological horror short, Jennifer Is Dead, the black comedy For Pete's Wake!, and guest spots on Without a Trace and Castle. Tallman later appeared in the 2009 horror film Dead Air, and in InAlienable (2008) Tallman plays Dr Klein, a crony of the evil scientist. Tallman played Holly in Atlas Shrugged: Part II (2012).
Ms. Tallman has performed voice roles including playing the leading part of evil detective Jean Richmond in the Radio Repertory Company of America's production of 'Lives of the Cat' and in some of the Anne Manx sequels (sold as radio plays on CD).
In 2011, Tallman published her autobiography Pleasure Thresholds - Patricia Tallman's Babylon 5 Memoir.
In 2012, Tallman became CEO and executive producer of Studio JMS in partnership with writer, director and producer J. Michael Straczynski. In 2013, she left the company. She is now the CEO of Quest Retreats, a VIP adventure excursion company with annual events in Hawaii, London, New Zealand, and South Africa.
In May 2014, Tallman played the male role of Lespere in a theatrical production of Ray Bradbury's "Kaleidoscope" at Sci-Fest LA: the 1st Annual Los Angeles Science Fiction One-Act Play Festival.
In May 2015, Tallman played the wife in a comedy called A Logic Called Joe at the second Sci-Fest LA.
Tallman is a leading fund-raiser for Penny Lane, a center for abused children in California. She has one child, a son named Julian. The actress met Jeffrey Willerth while filming the TV series Babylon 5. They were married in 1999 and divorced several years later. Tallman dated the writer J. Michael Straczynski "for quite a while", ending in early 2013.