Born in Lynn, Massachusetts, she studied acting at New York City's prestigious Neighborhood Playhouse. Grimes made her debut on the New York stage in May of 1955 in Jonah and the Whale. In 1956, she appeared in the off-Broadway production, The Littlest Revue and that same year she married Canadian actor Christopher Plummer with whom she had a daughter, actress Amanda Plummer, but the year after her lead role in the 1959 Noel Coward play Look After Lulu, they were divorced.

She was then given the starring role in the 1960 musical comedy The Unsinkable Molly Brown for which she won a Tony Award.

In 1966, Grimes starred in her own television show, The Tammy Grimes Show, as a present-day character based on Molly Brown, but it ran for only a month, although an additional six episodes had already been made; ironically, she had turned down the part of "Samantha" on Bewitched for which she had had right of first refusal. A bad career move, but considering the mortality rate for the actors on that sitcom, perhaps she made the right decision.

During her career, she spent several seasons at the Stratford Festival of Canada in Stratford, Ontario and has appeared in a number of television series and motion pictures. Grimes has also entertained at various New York city night clubs and recorded several albums of songs. Her voice can be heard in romantic duets on some of Ben Bagley's anthology albums of Broadway songs under his Painted Smiles record label. In 1982, she hosted the final season CBS Radio Mystery Theater.

Tammy Grimes was inducted into the (American) Theater Hall of Fame in 2003.

Active in American politics, she is a member of the Republican Party.

Awards:

Tony Award for Best Featured Actress in a Musical - The Unsinkable Molly Brown (1960) Theatre World Award - Look After Lulu (1959) Tony Award for Best Actress in a Play - Private Lives (1969) Broadway Plays (partial):

The Unsinkable Molly Brown (1960) High Spirits (1964) Private Lives (1969) A Musical Jubilee (1975) California Suite (1976) Tartuffe (1977) Trick (1979) 42nd Street (1980) Orpheus Descending (1989) Filmography (partial):