Fox has performed in many stage productions during her career, and is best known for her television roles as Luann Corbin in the NBC/CBS police drama series In the Heat of the Night (1989–1995), and as Hanna Young in the Oprah Winfrey Network prime time soap opera, The Haves and the Have Nots (2013–2021).

Fox has also appeared in a number of films, most notably playing the leading role in the 2020 thriller A Fall from Grace.

[4] Fox made her big-screen debut playing Katie Bell in the comedy-drama film Driving Miss Daisy (1989) starring Morgan Freeman and Jessica Tandy.

She later joined the cast of NBC police-drama series In the Heat of the Night in its third season, playing Luann Corbin.

[8] Her other stage credits include For Colored Girls Who Have Considered Suicide / When the Rainbow Is Enuf, Antony and Cleopatra, The Comedy of Errors, A Raisin in the Sun, The Colored Museum, The Amen Corner, The Boys from Syracuse, Bessie's Blues, Little Shop of Horrors and The Rocky Horror Picture Show.

In 2019, Fox was cast for the second season of the HBO drama series Big Little Lies as Zoë Kravitz’s character's mother Elizabeth Howard.

[16][17][18] Along with the cast, she was nominated for Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series.

[23] Chicago Sun-Times critic Richard Roeper wrote in a review: "Best of all is seeing Crystal Fox getting her moment in the spotlight and absolutely shining.