Swinton, distinguished by her ethereal features, has avoided mainstream films, opting instead to establish herself on the independent circuit. She appeared in each of Derek Jarman's films, beginning with Caravaggio (1986). She also starred in his biopic Wittgenstein (1993), his last feature before his death from AIDS in 1994. Swinton earned notice on these shores for Orlando (1992), in which she played the gender-bending title character in the film adaptation of Virginia Woolf's novel. Swinton's multidimensional performance as a mother willing to protect her son at any cost in The Deep End (2001) earned her wide praise and talk of an Oscar. Her other films include Sexual Perversions (1996) and The Beach (2000).
Swinton started acting as a student at Cambridge University. After earning a degree in social and political sciences, she appeared in productions for Edinburgh's Traverse Theatre and the Royal Shakespeare Company.