Played by: John Ritter
- Attractive Bent-Gender: When dressed in drag in the Season 4 episode "Jack on the Lam." Chrissy's date found him especially hot.
- Camp Straight: Which certainly helps when pretending to be gay.
- Casanova Wannabe
- Catch Phrase: "Oh lordy, lordy, lordy..."
- Chivalrous Pervert
- Cure Your Gays: Mr. Furley thinks his friendship with Jack did the trick when he moves in with a woman in the series finale.
- Faux Yay: Jack must pretend to be gay in front of the landlords so that he can live with two females.
- The Klutz
- Meaningful Name: Jack Tripper refers to the fact that Jack is a klutz.
- Mistaken for Gay
- Nice Guy
- The Pratfall:
- Punny Name: Just repeat his name slowly until you get the joke.
- Starving Student: The reason why he moves in with the girls.
- Supreme Chef: Jack attends cooking school for the first few seasons and later opens a French restaurant.
- Troll: Quite often when Mr Roper makes a crack about him being gay (or sometimes just to get rid of him), Jack gets his own back by pretending to flirt with him.
- Unresolved Sexual Tension: Multiple episodes suggest that he and Janet might have a thing for each other, but nothing ever comes of it, and in the series finale, they both end up marrying different people.
Played by: Joyce DeWitt
- Brainy Brunette
- Cloudcuckoolander: Although she's Closer to Earth than Chrissy, she often overhears things and Hilarity Ensues.
- Jerkass Ball: In the episode where she gets a blonde wig and starts to act more and more rude to everyone because she enjoys all of the attention it gives her.
- Ms. Fanservice: Frequently seen in short skirts and nighties, although more conservative than Chrissy.
- She's Got Legs: Joyce DeWitt had a gorgeous set of gams and always wore pantyhose on the show, refusing to appear bare-legged even when her character was supposedly naked under a towel. She even appeared in several commercials for L'eggs.
- Tomboy and Girly Girl: Janet was initially somewhat of a tomboy to Chrissy's girly girl, although this became less pronounced after the first season.
- Unresolved Sexual Tension: With Jack.
Christmas Noelle "Chrissy" Snow
Played by: Suzanne Somers (Seasons 1-5)
- Absentee Actor: Chrissy was absent from numerous Season 5 episodes because of behind-the-scenes problems with Suzanne Somers.
- Annoying Laugh: Her trademark snort.
- Brainless Beauty
- The Ditz
- Dumb Blonde
- Dumb Is Good
- Flanderization: In the first season, Chrissy was somewhat naïve but not really stupid; from Season 2 onwards, she Took a Level in Dumbass.
- Hair of Gold, Heart of Gold: She may not be too bright, but she compensates for that by being nice.
- Ms. Fanservice: The most of the show, frequently shown in bathing suits and short shorts.
- Preacher's Kid: Her father is a conservative Methodist minister, leading to the inevitable conflict over his daughter's decidedly non-traditional lifestyle. Amusingly, the actor who played Reverend Snow, Peter Mark Richman, is actually Jewish in real life.
- Put on a Bus: Following Suzanne Somers' departure.
- Punny Name: Which, she explains, is a result of her father being a big Bing Crosby fan.
Stanley and Helen Roper
Played by: Norman Fell and Audra Lindley (Seasons 1-3)
- And Starring: During their time on the show, Fell and Lindley got an "And Starring as the Ropers" credit.
- Aside Glance: Mr. Roper's specialty, after getting in a really good dig at his wife.
- Many times, this flirts with Breaking the Fourth Wall, as Mr. Roper looks straight at the camera (and thus the viewer) and smiles broadly.
- Awful Wedded Life: Albeit with occasional Aww, Look! They Really Do Love Each Other moments.
- Captain Obvious: Mr. Roper occasionally, prompting Mrs. Roper to reply, "Very good, Stanley."
- Cranky Landlord: Mr. Roper
- Iconic Outfit: Mr. Roper's cardigan sweaters, and Mrs. Roper's caftan dresses.
- Put on a Bus: They move across town (and to their own spinoff show) at the end of season 3.
- The Bus Came Back: They make a one-shot return in the season 5 episode "Night of the Ropers".
- Secret Keeper: Mrs. Roper finds out Jack isn't really gay in the second episode, but goes along with the charade in her husband's presence for the rest of their time on the show.
- Sexless Marriage: The Ropers appear to have one of these for the most part, much to Mrs. Roper's chagrin.
- Single-Issue Landlord: Mr. Roper will not stand for a single man sharing an apartment with two women. Hence Jack's need for Faux Yay.
Played by: Richard Kline (Seasons 2-8)
- Ascended Extra: He made a one-shot appearance in the first season before being brought back as a Recurring Character in Season 2.
- Casanova Wannabe
- Hollywood Tone-Deaf: Larry's singing is terrible, as Jack and crew discover when he inadvertently hires Larry to sing at his restaurant.
- Jerk with a Heart of Gold
- Promotion to Opening Titles: In Season 4.
- Small Name, Big Ego
Played by: Don Knotts (Seasons 4-8)
- Always Camp: His loud Seventies clothes seem to make sense only in his mind.
- Ascended Extra: Furley was originally supposed to be a one-time character, but Knotts fit in so efficiently with the rest of the cast that he became a series regular.
- Casanova Wannabe
- Catch Phrase: "Now hear this!"
- Dirty Old Man
- Expy: He's basically Barney Fife in a leisure suit.
- Locked Out of the Loop: Like Mr Roper, he is the only member of the cast who does not know that Jack is really straight.
- Unlike Mr Roper however, it is implied that, due to his own swingers' lifestyle, he himself would not mind the trio's living situation. It's just that his brother, the building's true owner, would not stand for it.
Played by: Jenilee Harrison (Seasons 5-6)
- Cute Clumsy Girl: Her primary attribute.
- Commuting on a Bus: In Season 6 she moves out of the apartment to attend UCLA, but continues to make regular appearances before eventually vanishing without explanation.
- The Ditz: Albeit a milder example than Chrissy.
- Statuesque Stunner: 5'8" Jenilee Harrison actually stood taller than John Ritter in heels, and absolutely towered over petite Joyce DeWitt.
- Suspiciously Similar Substitute
Played by: Priscilla Barnes (Seasons 6-8)
- Deadpan Snarker: Often.
- Hospital Hottie: Terri is a Registered Nurse.
- Meet Cute: A non-romantic example. She first meets Jack as a hostile, uncooperative patient at the hospital where she works as a nurse.
- Suspiciously Similar Substitute: Averted. She may be an attractive blonde but she's neither ditzy nor klutzy like her predecessors.