Mischa Anne Marsden Barton (born 24 January 1986) is a British-American fashion model, film, television, and stage actress, best known for her role as Marissa Cooper in the American television series The O.C..
Mischa Barton was born in Hammersmith,West London, to an Irish mother, Nuala (née Quinn), a photographer, and an English father, Paul Marsden Barton, a foreign exchange broker from Manchester.. She has two sisters, younger Hania and elder Zoe, a barrister in London. Her father's work took the family to New York City when Barton was six, and in 2006, ten days after her twentieth birthday,she became a naturalised citizen of the United States. She has retained her British citizenship and, in reference to her English roots, states "I actually feel more comfortable in England a lot of the time",yet stresses that, "I like people to discern that I'm an English-Irish girl who grew up in New York."
Barton graduated from the Professional Children's School in Manhattan in 2004, and took a summer short course called Acting Shakespeare at The Royal Academy of Dramatic Art in London, in June and July 2006, at Sir Richard Attenborough's urging, after he directed her in Closing the Ring.