Kristen Swanson was born December 19, 1969, in Mission Viejo, California. She dreamed of becoming an actress as a child, and got her start at the age of nine, appearing in a TV commercial for a dollhouse. By the time she was 13, Kristy had appeared in over 30 television ads. At this point, she gave up regular schooling to concentrate on acting, and her parents, who were physical education teachers, provided Kristy with home instruction. Around the same time, the Swanson family relocated to Los Angeles.

Glory landed bit parts in television series like Call to Glory (1985) and Alfred Hitchcock Presents (1986). She lucked out when she landed small roles in two very popular Brat Pack-era teen comedies; 1986's Pretty in Pink and Ferris Bueller's Day Off. She continued to work in made-for-TV movies and commercials, and was nominated for a Young Artist Award for her turn in Mr. Boogedy (1986). Swanson's first cinematic leading role, in Wes Craven's Deadly Friend (1986), earned her a second Young Artist nomination.

In 1987, Swanson starred in Flowers in the Attic, based on V.C. Andrews' classic horror novel. She received the Young Artist Award as Best Young Actress in a Horror or Mystery Motion Picture for her work. She returned to television for a recurring role on the CBS primetime soap Knots Landing during the 1987-88 season. A more prominent role in the Aaron Spelling-produced Nightingales on NBC, where she played a student nurse, abruptly ended after only one season (1988-89). Swanson returned to the big screen with roles in the largely forgotten Dream Trap and Diving In (both 1990). In 1991, she appeared in Hot Shots! and played the lead in the dismal Mannequin 2: On the Move.

But her career received a big boost in 1992 when she played the title character of Buffy Summers in Buffy the Vampire Slayer. Portraying a cheerleader who learns she has been chosen to rid the world of evil vampires, Kristy turned in a dazzling performance, but the film didn't do well at the box office. It did become a hot video rental, however, which helped spawn the successful TV series starring Sarah Michelle Gellarin the title role.

Swanson's athletic prowess came in handy for her portrayal of a tennis star in 1993's The Program. The following year, she starred in The Chase, appearing as the daughter of a millionaire taken hostage by an innocent Charlie Sheen on the run from the law. For Higher Learning (1995), Kristy received some of her best reviews, playing a naïve college freshman coming to terms with her homosexuality. Her performance in The Phantom (1996), based on the popular comic strip, was overshadowed by then unknown Catherine Zeta-Jones, who played the movie's voluptuous villainess.

In 1997, Swanson starred as a seductive sociopath in the ABC made-for-TV movie, Bad to the Bone. That same year, she also appeared on the big screen in Lover Girl and 8 Heads in a Duffel Bag, a comedy co-starring Joe Pesciand David Spade. In 1998, she played a gossipy Southern socialite in Meeting Daddy, and returned to primetime television for the 1998-'99 season of Early Edition on CBS.

The big screen beckoned once again, and Swanson was perfectly cast as Adam Sandler's girlfriend (who ends up leaving him) in the box-office blockbuster Big Daddy (1999). In Dude, Where's My Car?????????????????????????????????????????????????????????????? (2000), Kristy played the appropriately named Christie Boner, a ditzy yet seductive blonde bombshell. She was then cast as a meddling cruise-line executive on the CBS midseason replacement comedy Grapevine, which was promptly canceled.

In 2001, she appeared in the made-for-TV movie Zebra Lounge, and co-starred on the big screen in Soul Assassin. The year 2002 found the actress playing a psychiatrist in Silence, and in what was perhaps an attempt at shedding her "girl next door" persona, Kristy bared all in the November issue of Playboy.