- Acting for Two: Sort of. In the first opening sequence, Jack gets distracted by a brunette walking by and takes a tumble on his bike. The brunette? Suzanne Somers with a wig. Justified since the show was still in pilot stages when that was filmed so they had to be frugal.
- Hostility on the Set: Suzanne Somers caused so much friction onset during the fifth season that she didn't speak to John Ritter and Joyce DeWitt for over thirty years.note
- Irony as She Is Cast: Peter Mark Richman, who made three appearances on the show as Chrissy's Methodist minister father, Reverend Luther Snow, is actually Jewish in real life.
- Old Shame: "Shame" might be stretching it, but Priscilla Barnes says she was miserable the entire time. She's called it the three worst years of her life, and tried to walk, but couldn't get out of her contract.
- Real-Life Relative: In the show's opening (beginning with the sixth season), a toddler walks up to Joyce DeWitt as she is feeding a goat. The toddler is Jason Ritter (son of John Ritter). This is revealed by DeWitt in a bonus feature of the Season 4 DVD.
- Recycled Script: An early episode had the roommates trying to hide a recently adopted pet from Mr. Roper. Towards the end of the series' run, a similar plot (with a different animal, Mr. Furley and Terri) was used. John Ritter himself later acknowledged the trope and said that this was when he realized the series was starting to run out of ideas.
- Troubled Production: The show is so notorious for its on-set drama, a TV movie was made in 2003 about its troubled history. Actual line from Brian Dennehy: "The inmates are running the asylum!"
- It was stuck in the pilot stage for a long time. Peter Stone wrote one pilot set in New York that was never filmed. Larry Gelbart wrote another one set in North Hollywood that was filmed (with John Ritter, Valerie Curtin, and Suzanne Zenor), but not used when the show was ousted from ABC's fall schedule. CBS then offered to take the show, but ABC backtracked and agreed to air the show mid-season if the pilot was rewritten and reshot with a new cast. Don Nicholl, Michael Ross, and Bernie West wrote a third pilot script set in Santa Monica, and it was shot with John Ritter as Jack, Joyce DeWitt as Janet, and Susan Lanier as Chrissy (taking over for Denise Galick, who was fired two days before shooting). Executives disliked Lanier's portrayal of Chrissy, and producers were so desperate to find a new one, they basically fast-forwarded through all the audition tapes for the character before eventually settling on Suzanne Somers one day before she was supposed to be on-set. However, John Ritter was almost fired before the pilot taped again, with executives believing his performance was too effeminate. ABC Entertainment president Fred Silverman successfully fought to keep Ritter on the show, and the pilot was shot a third time before it was finally on the air.
- Suzanne Somers didn't get along with any of her co-stars, especially Joyce DeWitt. Partway through the series, a TV Guide cover showed Somers front-and-center, with DeWitt and Ritter in the background, infuriating them both. Once contract re-negotiations began in Season 5, she demanded a higher salary than her co-stars, feeling that her being Ms. Fanservice was partly responsible for the show's success. When executives refused, her diva antics began. She frequently showed up on set late, and often not at all. It got so bad, the writers had to pen two versions of the scripts: one with Chrissy and one without Chrissy. This prompted producers to severely reduce her role in the show for the remainder of her contract. It was explained that her character had gone away to be with her sick aunt, and she only appeared in quick telephone scenes toward the end of each episode, shot alone at night/early morning with no studio audience, and away from her angry co-stars. Once her contract was up, producers refused to renew it, and her character completely vanished for the last few seasons with no explanation, prompting Somers to sue ABC for $2 million, though she was only granted about $30,000. Somers' relationship with the rest of the cast and crew was severely strained, and she never spoke to Joyce DeWitt for over 30 years.
- Somers' replacements for the rest of the show didn't have it much better. Jenilee Harrison was brought on as Chrissy's cousin Cindy as a quick fill-in for Somers. While she got along well with the cast and crew, she was only seen as a temporary character, and her role got smaller and smaller until she was off the show for good. Priscilla Barnes (who played permanent new character Terri) had a miserable and "uncomfortable" time on set, and she asked to be released from her contract after taping only a couple episodes. The executives refused, and she remained on the show until the end, later referring to it as the worst experience of her life. Despite this however, she got along well with the cast and crew.
- Norman Fell and Audra Lindley were screwed over when their characters were spun off into their own show, The Ropers, following the third season. Norman Fell was very uneasy about doing the spinoff because of the security he already had doing a regular sitcom. He came to a compromise, and he and Lindley were promised a return to Three's Company if The Ropers lasted less than a season. It did go on to last one successful (6-episode) season before getting Screwed by the Network and getting cancelled at the end of its second season for poor ratings. The Ropers made only one final guest appearance on Three's Company, and they were permanently replaced with Don Knotts as Mr. Furley.
- Ann Wedgeworth was brought on in Season 4 as a regular cast member named Lana Shields, a neighbor attracted to John Ritter's character. However, her schtick got old quickly (John Ritter himself complained to the writers, wondering why a character as sex-crazed as Jack would repeatedly refuse the advances of a beautiful, sexually voracious woman; the only explanation the writers would give him is that Jack would be turned off by the fact that Lana was older than him, though only by about ten years). Writers found themselves with less to do with her character, and her role was reduced after just a few episodes. Insulted, Wedgeworth successfully asked to be released from the show.
- In addition, the show's other spinoff/sequel, Three's a Crowd, continued the story with Jack and his female roommate. Pre-production for the show was done in secret from the rest of the cast and crew, and auditions were held for Jack's roommate during the Christmas break. When Joyce DeWitt came in to set up her dressing room for the upcoming episodes, she accidentally walked in on the auditions. She and Priscilla Barnes felt betrayed by the goings-on, and DeWitt's relationship with the producers and Ritter was strained for the rest of the show, although she reconciled with Ritter many years later. Three's a Crowd, meanwhile, was axed after one season.
- Wag the Director: Joyce DeWitt refused to ever be shown bare-legged and always wore pantyhose when her legs were visible. Her commitment to hosiery earned her an endorsement deal with L'eggs brand pantyhose.
- What Could Have Been: Billy Crystal auditioned for the role of Jack Tripper.
- You Look Familiar:
- Jeffrey Tambor, now fairly well known for playing George Bluth Sr., appeared in several episodes, each time as a different character. And that's not even counting his regular role on the spinoff The Ropers.
- Jordan Chaney appeared in a third-season episode as a used-car dealer who employs Jack as a live-in cook (and whose wife keeps hitting on him), before becoming a semi-regular as Jack's boss Mr. Angelino.
Trivia / Three's Company