She is also a four-time Tony Award nominee for her work on Broadway, receiving nominations for Plenty (1983), A Moon for the Misbegotten (1984), Serious Money (1988) and Spoils of War (1989).
[1] Her mother, whom Nelligan has described as "very powerful, very brilliant and very, very crazy",[2] suffered from alcohol abuse and other psychological problems, and was institutionalized.
[6] In August 1972, Nelligan launched her professional stage career as a "funny and convincing" Corie in the Bristol Old Vic production of Barefoot in the Park by Neil Simon.
[6] In the Bristol Old Vic studio space in the following April she took the role of Leila in The Screens, an abridgement by Howard Brenton of Jean Genet's savage Les Paravents.
In 1977, again with the National Theatre, Nelligan gave a "stunning" performance as Marianne, opposite Stephen Rea, in Horváth's Tales from the Vienna Woods directed by Maximilian Schell.
In 1981, she starred opposite fellow Canadian Donald Sutherland in Eye of the Needle, a wartime espionage thriller based on the Ken Follett best-selling novel.