Mischa Anne Marsden Barton (born 24 January 1986) is a British-American film, television, and stage actress. She began her career onstage, appearing in Tony Kushner's Slavs! and took the lead in James Lapine's Twelve Dreams at New York City's Lincoln Center. She made her screen debut with a guest appearance on the American soap opera All My Children (1995) and voicing Betty Ann Bongo on the Nickelodeon cartoon series KaBlam! (1996–97). Her first significant film role was as the protagonist of Lawn Dogs (1997), a drama co-starring Sam Rockwell. She appeared in major pictures such as the romantic comedy Notting Hill (1999) and M. Night Shyamalan's psychological thriller The Sixth Sense (1999). She also starred in the indie crime drama Pups (1999).
Barton later appeared in the independent drama Lost and Delirious (2001) and guest-starred as Evan Rachel Wood's girlfriend on ABC's Once and Again (2001–02). She played Marissa Cooper in the Fox television series The O.C.(2003–2006), for which she received two Teen Choice Awards. The role brought Barton into mainstream fame, and Entertainment Weekly named her the "It Girl" of 2003.
Barton has since appeared in the comedy remake St Trinian's (2007), the Richard Attenborough–directed drama Closing the Ring (2007) and Assassination of a High School President (2008). She returned to television, starring in the short-lived Ashton Kutcher-produced CW series The Beautiful Life (2009).
In 2012, she returned to the stage, performing in the Irish production of Steel Magnolias. She also appeared alongside Martin Sheen in Bhopal: A Prayer for Rain (2014). She has garnered critical praise for her roles in independent films, with the Los Angeles Times praising her "standout" performance in Starcrossed (2014). Barton was cast in the first season of the MTV series The Hills: New Beginnings (2019–2021), a reboot of The Hills. In 2023, she was cast in an extended guest role for the rebooted Australian soap opera Neighbours on Amazon Freevee and Network 10.
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Known For

Invitation to a Murder
Miranda Green
2023

Deserted
Jae
2016

Swat: Unit 887
Agent Melanie Hamlin
2015

Operator
Pamela Miller
2015

Checkmate
Lauren Campbell
2015

American Beach House
Ms. Maureen
2015

L.A. Slasher
The Actress
2015

The Hoarder
Ella
2015

Zombie Killers: Elephant's Graveyard
Toni
2015

Hope Lost
Alina
2015

Throwdown
Lisa Thoams
2014

A Prayer for Rain
Eva
2014

Starcrossed
Kat
2014

Mining for Ruby
Jessica King
2014

A Resurrection
Jessie
2013

I Will Follow You Into the Dark
Sophia Monet
2012

Apartment 1303 3D
Lara Slate
2012

Cyberstalker
Aiden Ashley
2012

Beauty and the Least
Amy Warner
2012

You and I
Lana
2011

Don't Fade Away
Katherine Morrison
2010

Homecoming
Shelby Mercer
2009

Walled In
Sam Walczak
2009

Assassination of a High School President
Francesca Fachini
2008

St Trinian's
JJ French
2007

Virgin Territory
Pampinea
2007

Closing the Ring
Young Ethel Ann
2007

The Oh in Ohio
Kristen Taylor
2006

Octane
Natasha 'Nat' Wilson
2003

A Ring of Endless Light
Vicky Austin
2002

Tart
Grace Bailey
2001

Julie Johnson
Lisa Johnson
2001

Lost and Delirious
Mary 'Mouse' Bedford
2001

Paranoid
Theresa
2000

Skipped Parts
Maurey Pierce
2000

The Sixth Sense
Kyra Collins
1999

Pups
Rocky
1999

An Off-Beats Valentine's
Betty Ann Bongo (voice)
1999

New York Crossing
Drummond
1996
Murder at the Embassy
Miranda Green

Spree
London
2020

The Cat and the Moon
Jessica Peterson
2019

The Hills: New Beginnings
Herself · (12 episodes)
2019

Painkillers
The Girl / Sarah Mendelsohn
2019

The Basement
Kelly Owen
2018

The Toybox
Samantha
2018

Papa
Jennifer
2018

Monsters at Large
Katie Parker
2018

Ouija House
Samantha
2018

The Joneses Unplugged
Rebecca Jones
2017

The Malevolent
Ms Lowell
2016

Executor
Tara
2016

Recovery Road
Olivia · (1 episode)
2016

The Beautiful Life: TBL
Sonja Stone · (5 episodes)
2009

Chris Moyles' Quiz Night
Self · (1 episode)
2009

Dancing with the Stars
Self - Contestant · (3 episodes)
2005

The Friday Night Project
Self - Host · (1 episode)
2005

On Air with Ryan Seacrest
Self - The O.C. · (1 episode)
2004

The Ellen DeGeneres Show
Self · (1 episode)
2003

The O.C.
Marissa Cooper · (76 episodes)
2003

Punk'd
Self · (1 episode)
2003

Jimmy Kimmel Live!
(1 episode)
2003

Fastlane
Simone Collins · (1 episode)
2002
Frankie & Hazel
Francesca 'Frankie' Humphries
2000

Once and Again
Katie Singer · (8 episodes)
1999

Notting Hill
12-year-old Actress
1999

DragonMan: The Adventures of Luke Starr
Crystal Starr

Lawn Dogs
Devon
1997
Sleepwalker
Joelle
Bad News on the Doorstep
The Tony Danza Show
Self · (1 episode)
2004

Law & Order: Special Victims Unit
Gladys Dalton · (1 episode)
1999

The View
Self · (1 episode)
1997

KaBlam!
Betty Ann Bongo (voice) · (26 episodes)
1996

E! True Hollywood Story
Self (archive footage) · (1 episode)
1996

Late Night with Conan O'Brien
Self - Guest · (1 episode)
1993

LIVE with Kelly and Mark
(1 episode)
1988

Neighbours
Reece Sinclair · (60 episodes)
1985

Entertainment Tonight
Self · (4 episodes)
1981