Swinton worked with the Traverse Theatre in Edinburgh, and the Royal Shakespeare Company before embarking on a career in film in the mid-1980s. Her early film work included several film roles for director Derek Jarman, notably War Requiem (1989) playing a nurse opposite Sir Laurence Olivier as an old soldier. In 1991, Swinton won the Volpi Cup Best Actress award for her role in the postmodern film Edward II. Swinton also played the title role in Orlando, Sally Potter's film version of the novel by Virginia Woolf.

Swinton gained great artistic acclaim for a period in 1995 when she developed a performance/installation art piece in which as a live exhibit in the Serpentine Gallery, London, she was on display to the public for a week, asleep or apparently so, in a glass case, as a piece of performance art. The piece is often erroneously credited to Cornelia Parker, whom Swinton invited to collaborate for the installation in London. The following year, the performance, entitled The