Davis was in St. Matthews, South Carolina, USA to parents Mae Alice Davis, a maid, and Dan Davis, a horse trainer. She majored in theater at Rhode Island College and graduated in 1988. She also attended the Juilliard School for four years but regrets the experience.
Davis started in theater and was awarded the Tony Award for Best Performance by a Featured Actress in a Play for her portrayal of Tonya in the play, King Hedley II. Davis has several minor parts in film and television before starring in the 2011 film, The Help, for which she is most famous on a mainstream scale.