In 2007, Barton appeared in the films The Oh in Ohio and the comedy film Virgin Territory with Hayden Christensen.
She also joined Shirley Mac Laine and Christopher Plummer in Richard Attenborough's war drama Closing the Ring.
She guest-starred in eight episodes of the television series Once and Again as Jessie Sammler's (Evan Rachel Wood) girlfriend, Katie Singer.
In 2001, she returned to film and starred in the independent Canadian drama, Lost and Delirious, based on the novel The Wives of Bath by Susan Swan.
C., about affluent teenagers with stormy personal lives who reside in scenic Orange County, California.Barton won critical favour for her role, with Janet Maslin of The New York Times praising her "poised" performance Barton then appeared in Notting Hill (1999) and The Sixth Sense (1999).Both films were critically and commercially successful, respectively earning 3,889,700 and 2,806,292.The film was met with mixed reviews, but the performances of Barton and her co-stars Piper Perabo and Jessica Paré were widely praised.She also starred in Julie Johnson (2001) alongside Lili Taylor and Courtney Love, playing the daughter of a woman in a lesbian relationship.During her time on the show, Barton garnered several Teen Choice Awards.