Julia Kathleen Nancy McKenzie CBE (born 17 February 1941) is an English actress, singer, presenter, and theatre director. ​She was awarded the Laurence Olivier Theatre Award in 1983 (1982 season) for Best Actress in a Musical, Guys and Dolls. She was awarded the Laurence Olivier Theatre Award in 1994 (1993 season) for Best Actress in a Musical for her performance in Sweeney Todd at the Royal National Theatre.

She was awarded the 1987 London Evening Standard Theatre Award for Best Actress for her performance in Woman in Mind.

Was nominated for Broadway's 1977 Tony Award as Best Actress (Featured Role - Musical) for "Side by Side by Sondheim" (under the name "Julie N. McKenzie").