Shannyn Marie Kahololani Sossamon was born October 3, 1978 in Honolulu, Hawaii but grew up in Reno, Nevada.  She and her sisters formed a band called WarPaint with their friends during their younger days.  Shannyn studied at Galena High School and shortly after her high school graduation, she went to Los Angeles to pursue a dancing career.  She attended Dance Unlimited and earned a living by appearing in TV commercials and by being a DJ in local clubs.  Her DJ work took her as far as assisting in actress Gwyneth Paltrow's birthday party in 1997.  It was there that she got discovered by casting director Francine Maisler.

In 2001, Shannyn Sossamon had her first leading role as Lady Jocelyn in Brian Helgeland's A Knight's Tale.  Her performance in the movie earned her an MTV Breakthrough Female Performance Award in 2002.  She also appeared in the films 40 Days, 40 Nights, The Order, Kiss Kiss Bang Bang, The Holiday, One Missed Call and Catacombs among others.  Shannyn was seen on TV shows Moonlight and Law & Order: Special Victims Unit.

She did a TV commercial for GAP Jeans and was also part of several music videos such as Cher's “Strong Enough,” Korn's “Make Me Bad,” The Goo Goo Doll's “Dizzy,” Mick Jagger's “God Gave Me Everything,” Black Heart's Procession's “Not Just Words” and Deborah Cox's “It's Over Now.”

She was listed as one of the 102 sexiest women in the world by Stuff magazine, and was named one of the Maxim's Hot 100 of 2002.  She was also featured on The Times Magazine, People Weekly, Playboy, Movieline and Premiere.

Kira Klay is played by Shannyn Sossamon on FX's drama series Dirt.  The show focuses on DirtNow's editor-in-chief Lucy Spiller, the people around her and the publication of the first ever glossy tabloid.  Klay is a friend and fellow actress to Julia Mallory (Laura Allen).  Mallory's boyfriend, Holt McLaren, is a has-been actor and is struggling to regain his celebrity status.  When McLAren learns of Klay's pregnancy, he makes a deal with Spiller and reveals the information to the tabloid editor in exchange for a good publicity that will make him appear as if he's still in demand.