Hicks was born in New York City, the daughter of Jackie, a homemaker, and Walter Hicks, an electronics salesman. She has Irish and English ancestry. Her family moved to Scottsdale, Arizona during her childhood. She was a cheerleader at Gerard Catholic High School in Phoenix, Arizona and a member of The National Honor Society, before graduating in 1969. After attending Saint Mary's College, where she studied English Literature and Theology, Hicks won a prestigious acting fellowship to Cornell University. While at Cornell, she was a member of the Ithaca Repertory Theater Company.

After graduating from Cornell University with a Masters of Fine Arts degree, Hicks headed to New York in August 1976, where she immediately got work in television commercials. Two weeks after arriving in New York, she landed her first major TV role as the newly recovered pediatrician Dr. Faith Coleridge #3 on ABC soap opera, "Ryan's Hope." A year and half later, she left her role on "Ryan's Hope" when she was cast to star alongside Jack Lemmon (as Scottie) in Bernard Slade's 1978 Broadway play, "Tribute," in which she played the young model Sally Haines, who Scottie sets up with his estranged son (Robert Picardo). That same year, she starred as Valerie in the CBS TV movie and TV series pilot called “Sparrow.”

In Sidney Lumet's 1984 film, “Garbo Talks,” Hicks was aspiring-actress Jane Mortimer. Hicks also played Bill Murray's socialite fiancée, Isabel, in the 1984 remake of “The Razor's Edge.” Hicks received a Saturn Award nomination for Best Supporting Actress for her work in 1986's “Star Trek IV: The Voyage Home.” That same year, she played Carol Heath in Francis Ford “Coppola's Peggy Sue Got Married.” In 1987's “Like Father, Like Son,” Hicks played Dr. Amy Larkin.

Hicks co-starred with Christopher Plummer, as his estranged daughter, Tina Boyer, in the Showtime movie channel's 1988 movie, Souvenir. She played Karen Barclay in the 1988 horror film, Child's Play. Her performance won her a 1988 Best Actress Saturn Award. In 1989, she starred opposite Tony Danza in “She's Out of Control,” as his girlfriend, Janet Pearson.

In 1996, she was cast as Annie Camden on The WB's family drama "7th Heaven." In 1997, Hicks played flight attendant, Maggie, one of Ray Liotta's victims in "Turbulence." The same year, Hicks played next door neighbor, Ms. Lewis, in Michael Davis' coming-of-age film, "Eight Days a Week."

In 2008, Hicks also starred in the Lifetime channel's movie “Poison Ivy: The Secret Society” as Dean Elisabeth Graves. Also in the 2009 Lifetime Movie Network film, “Stranger with My Face,” she played the widowed mother Shelley Stratton. She plays Mom in the 2009 independent short film “You're a Wolf,” co-starring with Michael Gross and Jesse Bradford. Hicks is featured in “My Name Is Jerry,” an independent film shot mostly in Muncie, Indiana. Hicks won the award for Best Actress in a Supporting Role from the 2009 International Filmmakers Festival for her portrayal as Dana.

Hicks met her future husband, special effects make-up artist, and the designer and executor of the "Chucky" doll, Kevin Yagher, on the set of the film “Child's Play.” Hicks and Yagher were married on May 19, 1990. The two have a daughter named Catie, who was born in January 1992. Hicks is a devout Roman Catholic.