Manville built a career as a distinctive theatre actress, appearing in new plays at the Royal Shakespeare Company's Warehouse and Royal Court Theatre from 1978. She met Mike Leigh in 1979, when he was looking for RSC actors who could improvise. In the 1980s, her work for the Royal Court included Andrea Dunbar's Rita, Sue and Bob Too (1981) and Caryl Churchill's Top Girls (1982) and Serious Money (1987). She also starred in the Top Girls Off-Broadway production in 1983. For the RSC, she starred in As You Like It (1985) and Les Liaisons Dangereuses (1985–86). She made her film debut in 1985s Dance with a Stranger directed by Mike Newell, and went on to appear in Sammy and Rosie Get Laid (1987) directed by Stephen Frears, and High Season (1987). Back on the stage, she starred in The Cherry Orchard at the Aldwych Theatre in 1989, directed by Sam Mendes, and in Three Sisters at the Royal Court in 1990.
