Dad’s Army is a British sitcom about the Home Guard in the Second World War. It was written by Jimmy Perry and David Croft and broadcast on BBC television between 1968 and 1977. The series ran for 80 episodes in total, plus a radio series, a feature film and a stage show. The series regularly gained audiences of 18 million viewers during the 1970s and is still repeated today on BBC Two.

The British Home Guard consisted of local volunteers otherwise ineligible for military service, usually owing to age, and as such the series starred several veterans of British film, television and stage, including Arthur Lowe (1915–1982), John Le Mesurier (1912–1983), Arnold Ridley (also a veteran playwright; 1896–1984) and John Laurie (1897–1980).

Relative youngsters in the regular cast were Ian Lavender (b.1946), Clive Dunn (b.1920), who was made-up to play the elderly Jones, and James Beck (1929–1973), the last-named dying suddenly part way through the programme’s long run despite being the second youngest cast member.

In 2004, Dad's Army was voted into fourth place in a BBC poll to find Britain's Best Sitcom. Previously, in a list of the 100 Greatest British Television Programmes drawn up by the British Film Institute in 2000, voted for by industry professionals, it was placed thirteenth.

The series has had a profound influence on popular culture in the United Kingdom, with the series' catchphrases and characters well known. It is also credited with having highlighted a hitherto forgotten aspect of defence during World War II. The Radio Times magazine listed Captain Mainwaring's "You stupid boy!" among the 25 greatest put-downs on TV

The show was set in the fictional seaside town of Walmington-on-Sea, on the south coast of England (although the external scenes were mostly filmed in and around Thetford, Norfolk). Thus, the Home Guard were on the front line in the eventuality of an invasion by the enemy forces across the English Channel, which formed a backdrop to the series.

The first series had a loose narrative thread, with Captain Mainwaring’s platoon being formed and equipped, initially with wooden guns and LDV armbands, and later on full army uniforms; the platoon were part of the The Queen's Own Royal West Kent Regiment.