She may be best known to international audiences for her role in the Hugh Grant and Julia Roberts film Notting Hill, in which she played wheelchair user Bella.
In 1996 she played Mary in the BBC drama Our Friends in the North, a role for which she won three Best Actress awards in 1997: the British Academy Television Award, the Royal Television Society Award and the Broadcasting Press Guild Award. McKee appeared in several episodes of the Chris Morris spoof current affairs show, Brass Eye (1997, 2001), as reporter Libby Shuss.
On stage, McKee's credits include Harold Pinter's The Lover and The Collection at the Comedy Theatre in London.
In 2008 she appears in the BBC drama Fiona's Story and a West End revival of Chekhov's Ivanov.
McKee was awarded an Honorary Doctorate of Arts from the University of Sunderland in 2002.
She lives in East Dean in East Sussex with her husband Kez Cary to whom she has been married since 1989. McKee has been a vegetarian since 1982.