The middle of seven children, she was named after the S.S. Rosalind at the suggestion of her father, a successful lawyer. After receiving a Catholic school education, she went to the American Academy of Dramatic Art in New York, having convinced her mother that she intended to teach acting. In 1934, with some stock company work and a little Broadway experience, she was tested and signed by Universal. Simultaneously MGM tested her and made her a better offer. When she plead ignorance of Hollywood (while wearing her worst-fitting clothes), Universal released her and she signed with MGM for seven years.

For some time she was used in secondary roles and as a replacement threat to limit Myrna Loy's salary demands. Knowing she was right for comedy, she tried five times for the role of Sylvia Fowler in The Women. George Cukor told her to "play her as a freak"; she did and got the part. Her "boss lady" roles began with the part of reporter Hildy Johnson in His Girl Friday, through whose male lead, Cary Grant, she met her future husband, Grant's house guest at the time.

In her forties, she returned to the stage, touring "Bell, Book and Candle" in 1951 and winning a Tony for "Wonderful Town" in 1953. Columbia, worried the public would think she had the female lead in Picnic, billed her "co-starring Rosalind Russell as Rosemary" (she refused to accept an Oscar nomination as supporting actress). "Auntie Mame" kept her on Broadway for two years; the movie version was her last cinematic triumph.

Oscar nominations: My Sister Eileen, Sister Kenny, Mourning Becomes Electra, and Auntie Mame. In 1972 she received the Jean Hersholt Humanitarian Award for contributions to charity.
Interred at Holy Cross Cemetery, Culver City, California, USA, in the center of section M at the statue and cross. Son, Lance Brisson, born May 7, 1943. Died about three weeks after Patrick Dennis, the author of Auntie Mame, one of her most famous roles. She refused to be placed in the "best supporting" category when Columbia Pictures wanted to promote her for an Academy Award nomination for her role in Picnic. Many felt she would have won had she cooperated. Won Broadway's 1953 Tony Award as Best Actress (Musical) for "Wonderful Town," a musical based on the same source as her film My Sister Eileen, for which she received an Oscar nomination playing the same character. She also received a 1957 Tony Award nomination as Best Actress (Dramatic) for "Auntie Mame," a part she recreated in an Oscar-nominated performance in the film version Auntie Mame. She died after a long battle with breast cancer in 1976 at the age of 69, although initially her age was misreported because she had shaved a few years off her true age. She has a star on the Hollywood Walk of Fame at 1708 Vine Street In 1970, she accepted the Oscar for "Best Actress in a Supporting Role" on behalf of Helen Hayes, who wasn't present at the awards ceremony. Her performance as Hildy Johnson in "His Girl Friday" (1940) is ranked #28 on Premiere Magazine's 100 Greatest Performances of All Time (2006).