She graduated with a bachelor's degree in drama from Boston University in 1979. She was working as a model when director Sydney Pollack spotted her, and cast her in Tootsie (1982) as a soap opera actress. She followed this up with roles in the short-lived television series Buffalo Bill (1983-1984)) and Sara (1985). She received an Academy Award as Best Supporting Actress for her role in The Accidental Tourist (1988) and a Best Actress nomination for her role in Thelma and Louise (1991).
Davis has been married four times, including her current marriage. Her ex-husbands include Jeff Goldblum (with whom she co-starred in three films, including The Fly and Earth Girls Are Easy) from 1987-90, and Renny Harlin (who directed her in Cutthroat Island) from 1993-98. She is currently married to Dr. Reza Jarrahy since September 1, 2001, with whom she has one daughter, Alizeh (born April 10, 2002). She had a Caesarean section on May 9, 2004, to deliver her twins, Kian William Jarrahy and Kaiis Steven Jarrahy.
Davis guest-starred in early 2004 as Grace Adler's sister Janet on the NBC sitcom Will & Grace. She is currently starring in the ABC television series, Commander-in-Chief as the President of the United States, who ascends to the office after the sitting President dies. She had previously starred in the short-lived sitcom The Geena Davis Show (2000-2001).
Davis is also the founding member of SeeJane.org, an organization promoting gender equity and furthering the positive portrayal of women in movies and media. She is also honorary member of the Dads and Daughters organizations (DADs) who "provide men with tools to be better fathers and advocates for daughters".