The daughter of an Air Force career officer, Priscilla Barnes originally dreamed of becoming a dancer--a dream that was dashed when she slipped on the stage of the Hollywood Bowl and broke her leg. Priscilla then took on a series of odd jobs, including a waitress stint at Pips, a private Los Angeles club. There she made the acquaintance of actor Peter Falk who, impressed by Priscilla's all-American good looks and self-deprecating sense of humor, arranged for her to play a bit role on a 1976 Columbo episode. One thing led to another, and Priscilla found herself co-starring in the short-lived TV Charlie's Angels rip-off American Girls (1978). She was better-served with a sizeable supporting role opposite Michael Caine in the 1980 theatrical feature Sunday Lovers. In 1981, Priscilla was handed the unenviable task of replacing pin-up phenomenon Suzanne Somers (whom she'd never met) on the popular ABC sitcom Three's Company. In the light of the well-publicized clashes between Somers and her co-workers, much was made of Priscilla's cooperative nature and team spirit. She remained in her Three's Company role of nurse Teri Alden until the series' cancellation in 1984; she then dived into the Special Guest Star pool, making one-shot appearances on a variety of programs, including the obligatory "mystery killer" gig on Murder She Wrote. One of Priscilla Barnes' post-Three's Company assignments was the part of Hildy Granger on the pilot episode of the syndicated sitcom She's the Sheriff....a part played in the subsequent series by none other than Suzanne Somers!
- Father was a career Air Force officer.
- Was spotted by Bob Hope in a 1975 fashion show and asked to join his troupe of entertainers on a tour of veterans hospitals and military bases.
- Was Penthouse Pet of the Month under the name Joann Witty in the March 1976 issue. The magazine sought to republish the photos under her real name in 1983 after she became a regular on the sitcom Three's Company and she sued.
- In 1981, replaced Jenilee Harrison (who had replaced Suzanne Somers) in Three's Company.
- Was considered for the role of Willie Scott in Steven Spielberg's Indiana Jones and the Temple of Doom (1984), but could not accept due to shooting conflicts with her sitcom.
- Portrayed Hildy Granger on the 1987 pilot of the sitcom She's the Sheriff, a part that was subsequently played in the series by Suzanne Somers.
- Has toured and made public appearances with her Three's Company costars Joyce DeWitt and Richard Kline.