This is the list of actors from the main cast of the Three's Company television series.
- Norman Fell - played Stanley Roper, the original landlord of Hacienda Palms Apartments, in seasons 1-3
- Don Knotts - joins the cast as Ralph Furley, the quirky new landlord in season 4, remaining with the series thru the rest of the show's duration (Season 8).
- Richard Kline - appears as Larry Dallas, used car salesman, an upstairs neighbor and best friend of Jack's through the duration of the series's run
- Ann Wedgeworth - appears as Lana Shields, sexy forty-something neighbor of Jack, Janet and Chrissy in several episodes of season 4
- Priscilla Barnes - Joins cast as Terri Alden, a registered nurse, in season 5, staying with cast for the duration of the show's run
Recurring cast members
- Jordan Charney - appeared as Frank Angelino, owner of Angelino's Restaurant, then deed owner of the land Jack's Bistro sits upon; Jack's short-tempered, oftentimes duplicitous boss, in season 6-7
- Gino Conforti - played the part of Felipe Gómez, Jack's at-first jealous co-worker at Angelino's who later becomes a friend of Jack and the roommates, also works at Jack's Bistro, Jack's new restaurant who appears in seasons 6-7
- William Pierson - Plays the part of Dean Travers, the dean at Jack's cooking school who appears sporadically in several episodes during seasons 1-6
- Peter Mark Richman - appeared as Reverend Luther Snow, Chrissy's minister father, appears in several episodes in seasons 1 thru 4
- Paul Ainsley - appeared as Jim the Bartender at The Regal Beagle, the local restaurant/bar hangout of the roommates, from seasons 1-5