In the 1970s, Warren worked mostly on television, receiving a Golden Globe nomination for playing Dana Lambert in the CBS drama series Mission: Impossible (1970–71).

[3] Her television appearances through the decade included Dr. Kildare; Gunsmoke; The Mod Squad; Love, American Style; and The Carol Burnett Show.

[citation needed] Notable in television roles throughout the 1970s, Warren was leading lady Dana Lambert during the 1970–71 season of the CBS action drama Mission: Impossible.

[8] Warren played a fatefully and fatally gullible psychiatric patient opposite Peter Falk and George Hamilton in the 1975 Columbo episode "A Deadly State of Mind".

She received critical acclaim, as well as the Golden Globe Award for Best Actress – Television Series Drama in 1978, for the NBC miniseries Harold Robbins' 79 Park Avenue.

In 1981, Warren returned to the big screen starring alongside Ken Wahl, George Peppard, and Donald Pleasence in Race for the Yankee Zephyr, a New Zealand suspense-action-thriller film directed by David Hemmings.

The following year, she played ditzy gun moll Norma Cassidy in Blake Edwards' musical comedy Victor/Victoria for which she was nominated for a Golden Globe and Academy Award for Best Supporting Actress.

[10] Warren received another Golden Globe Award nomination for Best Supporting Actress for starring opposite Willie Nelson and Kris Kristofferson in the 1984 musical comedy film Songwriter.

[12] In 1985, she starred as one of the prime murder suspects, Miss Scarlet, in the comedy film version of the popular board game Clue.

[13] Warren played supporting roles in a number of movies, including Burglar (1987) with Whoopi Goldberg, Cop (1988) with James Woods, Worth Winning (1989) with Mark Harmon, Life Stinks (1991) with Mel Brooks and Pure Country (1992) with George Strait.

In Color of Night (1994) Warren played a nymphomaniac; the film was poorly received, and she was nominated for a Golden Raspberry Award for Worst Supporting Actress.

She had recurring roles on the NBC sitcom Will & Grace from 2001 to 2006 as Will Truman's father's mistress and in 2005 in the ABC comedy-drama Desperate Housewives as Susan Mayer's mother.

From 2008 to 2012, Warren played the role of Jinx Shannon, the lead character's alcoholic mother in the USA Network drama series In Plain Sight.

In 2022, she appeared as a regular cast member of the crime dramedy streaming series Panhandle, and had a featured role in the independent film It Snows All the Time.