As of 2005, she became the fourth star of The O.C. to get Punk'd. (Her co-star Adam Brody was Punk'd in 2004, Rachel Bilson was tricked by Ashton Kutcher in early 2005, and Benjamin McKenzie was punk'd in 2005.)
Most of her roles before The OC were R-rated, and usually involved sex, drugs, alcohol, horror, and homosexuality. She admits that she likes the "edgier" roles when acting. This corresponds to the recurring edgieness of her character.
Barton was born to an English father and an Irish mother, but moved to New York City when she was four years old. She has two sisters, Hania and Zoe. Barton graduated from the Professional Children's School in Manhattan in 2004.
Barton began her acting career at the age of nine in New York Theatre with a lead role in Slavs!, written by Tony Kushner. She took part in many plays, taking a lead role in James Lapine's Twelve Dreams. She made her film debut in Lawn Dogs, which won awards at film festivals around the world. Since then she has appeared in several films, including The Sixth Sense, Notting Hill, and Lost and Delirious, in which she starred.
Mischa Barton first appeared on television in 1994, as a younger Lily Montgomery in All My Children. She also had a one-time appearance in the Fox's show Fastlane, and appeared in the video for "Goodbye My Lover" by James Blunt. She has also appeared in Enrique Iglesias's video, Addicted.
Barton is also a model, with such prominent clients as Calvin Klein. She has appeared in advertisements for Aéropostale, bebe, Dooney and Bourke, JC (Jeans and Clothes), and Neutrogena. The executives at Neutrogena decided to make her the cover girl for their new worldwide ad campaign; in this regard Barton followed in the footsteps of fellow teen stars Jennifer Love Hewitt, Mandy Moore, and Kristin Kreuk. She also did a commercial for Keds sneakers.
- Guilty Pleasures (2007)
- Closing the Ring (2007)
- The OH in Ohio (2006)
- Octane (2003)
- Lost and Delirious (2001)
- Tart (2001)
- Julie Johnson (2001)
- Paranoid (2000)
- Skipped Parts (2000)
- The Sixth Sense (1999)
- Notting Hill (1999)
- Pups (1999)
- Lawn Dogs (1997)
- Polio Water (1995)
- TBL: The Beautiful Life (2009)
- Once and Again (2002 - 2003)
- A Ring of Endless Light (2002)
- Frankie & Hazel (2000)
- KaBlam! (1996 - 1997) (voice)
- All My Children (1996)
- New York Crossing (1996)
- Her height is five feet nine inches (175 cm).
- Barton's elder sister, Zoe, is a barrister in London.
- She is friends with Nicole Richie and has appeared with her on the cover of the Australian Who magazine.
- Although she had her ears pierced in her early teens, she later let the piercings heal up again, and could then only wear clip-on earrings. In 2009, she had her ears re-pierced especially for her role as Sonja Stone in the short-lived TV show, TBL: The Beautiful Life.
- Barton became a naturalized U.S. citizen in Los Angeles on February 3, 2006.
- In 2003, she had her belly button pierced especially for her role in Octane, but then removed the piercing and let it heal up once filming was completed.