Fawlty Towers is a British television sitcom written by John Cleese and Connie Booth, originally broadcast on BBC Two in 1975 and 1979. Two series of six episodes each were made. The series is set in Fawlty Towers, a dysfunctional hotel in the English seaside town of Torquay in Devon. The plots centre on the tense, rude and put-upon owner, Basil Fawlty (Cleese), his bossy wife Sybil (Prunella Scales), the sensible chambermaid Polly (Booth), and the hapless and English-challenged Spanish waiter Manuel (Andrew Sachs). They show their attempts to run the hotel amidst farcical situations and an array of demanding and eccentric guests and tradespeople.

Fawlty Towers was inspired by the Gleneagles Hotel in Torquay, where Cleese and the rest of the Monty Python group stayed in 1970. The snobby and eccentric owner, Donald Sinclair, was the inspiration for Basil Fawlty.

While some critics initially derided Fawlty Towers, it soon received general acclaim. In 1976 and 1980, it won the British Academy Television Award for Best Scripted Comedy. In 1980, Cleese received the British Academy Television Award for Best Entertainment Performance. The popularity of Fawlty Towers has endured and it is often re-broadcast. The show was ranked first on a list of the 100 Greatest British Television Programmes drawn up by the British Film Institute in 2000. In a 2001 poll conducted by Channel 4, Basil Fawlty was ranked second (to Homer Simpson) on their list of the 100 Greatest TV Characters. In 2019, it was named the greatest-ever British TV sitcom by a panel of comedy experts compiled by the Radio Times. The BBC profile for the series states that "the British sitcom by which all other British sitcoms must be judged, Fawlty Towers withstands multiple viewings, is eminently quotable ('don't mention the war') and stands up to this day as a jewel in the BBC's comedy crown." In 2023, Cleese suggested that a sequel series was being developed.

In May 1970, the Monty Python comedy group stayed at the now-demolished Gleneagles Hotel in Torquay, Devon, while filming on location in Paignton. John Cleese was fascinated with the behaviour of the owner, Donald Sinclair, later describing him as "the rudest man I've ever come across in my life". Among such behaviour by Sinclair was his criticism of Terry Gilliam's "too American" table etiquette and tossing Eric Idle's briefcase out of a window "in case it contained a bomb". Asked why anyone would want to bomb the hotel, Sinclair replied, "We've had a lot of staff problems." Michael Palin states that Sinclair "seemed to view us as a colossal inconvenience". Rosemary Harrison, a waitress at the Gleneagles under Sinclair, described him as "bonkers" and lacking in hospitality, deeming him wholly unsuitable for a hotel proprietor. "It was as if he didn't want the guests to be there." Cleese and his then-wife Connie Booth stayed on at the hotel after filming, furthering their research of its owner. Demolished in 2015, the building was replaced by a new retirement home named Sachs Lodge in memory of Andrew Sachs who played Manuel in the sitcom and who died in 2016.

Cleese was an occasional writer on the 1970s medical sitcom Doctor in the House and its follow-ons for London Weekend Television. An early prototype of the character that became known as Basil Fawlty was developed in an episode ("No Ill Feelings") of the third Doctor series (titled Doctor at Large). In this episode, the main character (played by Barry Evans) checks into a small-town hotel, his very presence seemingly winding up the aggressive and incompetent manager (played by Timothy Bateson) with a domineering wife. The show was broadcast on 30 May 1971.

Cleese said in 2008 that the first Fawlty Towers script he and Booth wrote was rejected by the BBC. At a 30th-anniversary event honouring the show, Cleese said,

Connie and I wrote that first episode and we sent it in to [BBC head of comedy] Jimmy Gilbert. The fellow whose job it was to assess the quality of the writing said (and I can quote [his note to me] fairly accurately), "This is full of clichéd situations and stereotypical characters and I cannot see it as being anything other than a disaster." Gilbert himself said that "You're going to have to get them out of the hotel, John. You can't do the whole thing in the hotel."

Cleese was paid £6,000 for 43 weeks of work and supplemented his income by appearing in television advertisements. He said "I have to thank the advertising industry for making this possible. Connie and I used to spend six weeks writing each episode and we didn't make a lot of money out of it. If it hadn't been for the commercials I wouldn't have been able to afford to spend so much time on the script."