Smart appeared in made-for-TV and feature films such as Flashpoint (1984) and Protocol (with Goldie Hawn, 1984) before being cast in the part that brought her stardom: ditsy blonde Charlene Frazier on the sitcom "Designing Women." Leaving the popular television series in 1991 to pursue meatier fare, Smart took on the role of a female serial killer in the TV movie Overkill: The Aileen Wuornos Story. Her other big-screen efforts include Homeward Bound: The Incredible Journey (1993), Guinevere (1999) and Snow Day (2000).
A two-time Emmy winner for guest appearances on "Frasier," Smart was Emmy-nominated for her portrayal of neurotic first lady Martha Logan on "24" and won the statuette for her supporting role in "Samantha Who?"