All Gas and Gaiters is a British television ecclesiastical sitcom which aired on BBC1 from 1966 to 1971. It was written by Pauline Devaney and Edwin Apps, a husband-and-wife team who used the pseudonym of John Wraith when writing the pilot. All Gas and Gaiters was also broadcast on BBC Radio from 1971 to 1972.

All Gas and Gaiters, predominantly farcical in nature, is set in the close of the fictional St Ogg's Cathedral and concerns intrigues and rivalries among the clergy in the Church of England. The bishop is easygoing; his friend the archdeacon is elderly, tippling, and still appreciative of attractive women; and the bishop's chaplain is naïve and accident-prone. Their wish to live a quiet bachelor life was continually threatened by the overbearing dean, who tried to bring by-the-book rule to the cathedral, and the dean's strident wife.

The title derives from a comic expression "all is gas and gaiters" (meaning "all is well"), uttered by an eccentric old gentleman clad in small-clothes and grey worsted stockings in Charles Dickens's 1839 novel Nicholas Nickleby, and later used by such writers as P. G. Wodehouse, Agatha Christie, and Powell and Pressburger (spoken in the film The Life and Death of Colonel Blimp). The phrase "all gas and gaiters" has had different meanings. Sometimes it has been used to mean "a satisfactory state of affairs" and sometimes it has had the meaning of "nonsense". The relevance of this phrase to Anglican clergy is that gaiters (worn over shoes) were part of the traditional dress of bishops and archdeacons.

The series initially aroused some controversy because of its portrayal of senior clergy as bungling incompetents, although some clergy enjoyed it. In the opening credits, St Albans Cathedral was shown as the fictional St Ogg's (but with the Crooked Spire of Church of St Mary and All Saints, Chesterfield added to the central tower). The background to the opening credits was actually the headmaster's garden of St Albans School. The name "St Ogg's" may have been taken from a fictional village in George Eliot's novel The Mill on the Floss.

The series proved to be the first of a number of comedies starring Derek Nimmo in similar bumbling clerical roles – Oh, Brother!, Oh, Father! and Hell's Bells – but is regarded as the best, partly because of a strong supporting cast (particularly the experienced farceur Robertson Hare as the archdeacon) and partly because it included some elements of gentle satire.

The pilot and first two series were videotaped in black-and-white. The third series was videotaped in colour, but was originally broadcast in monochrome. The fourth and fifth series were made and shown in colour.

The pilot episode was chosen to be the opening episode of the fifth series of Comedy Playhouse, the BBC's long-running comedy strand that showcased one-off potential sitcom pilots. The pilot episode received favourable reviews from the press and gained more viewers than all the episodes in the preceding series of the show. The BBC quickly commissioned Devaney and Apps to write six more episodes, which were taped in the studio later that year. Previously thought missing from the archives, the pilot was recovered in 2001 and received its first public screening at the BFI's annual Missing Believed Wiped event at the National Film Theatre on 20 October 2001.

Initially only one episode The Bishop Gets the Sack was thought to have survived from this series. However in 2001, two episodes were returned to the BBC archive following their Treasure Hunt campaign; when the series' creators Pauline Devaney and Edwin Apps returned film copies of the following episodes The Bishop Rides Again and The Bishop Sees a Ghost, since they personally requested copies of two episodes from BBC at the time, when they were trying to sell the series to the US.