The Bedsitting Room is a satirical play by Spike Milligan and John Antrobus. It began as a one-act play which was first produced on 12 February 1962 at the Marlowe Theatre in Canterbury, England. The Bedsitting Room was then adapted to a longer play and Bernard Miles put it on at the Mermaid Theatre, where it was first performed on 31 January 1963 before transferring several weeks later to the Duke of York's Theatre in London's West End.

The production included a coup de théâtre, when the character "Mate" (originally played in London by Spike Milligan) entered wearing a mixture of ragged military uniforms from across the centuries. Attached to his boots were long strips of canvas to which were attached pairs of boots. As he marched across the stage, the empty boots marched in time behind him. The play was considered a critical and commercial hit, and was revived in 1967 with a provincial tour, before opening at London's Saville Theatre on 3 May 1967. The script was later published in paperback book.

The play was presented in repertory by the Theatre Royal, York in 1972, and was also shown by Bench Theatre in Havant for seven nights in July 1981.

The play is set in a post-apocalyptic London, nine months after World War III (the "Nuclear Misunderstanding"), which lasted for two minutes and twenty-eight seconds – "including the signing of the peace treaty". Nuclear fallout is producing strange mutations in people; the title refers to the character Lord Fortnum, who finds himself transforming into a bed-sitting room (other characters turn into a parrot and a wardrobe). The plot concerns the fate of the first child to be born after the war.

A film based on the play was released in 1969. The film was directed by Richard Lester and the cast included Ralph Richardson, Arthur Lowe, Rita Tushingham, Peter Cook, Dudley Moore, Michael Hordern, Marty Feldman, Harry Secombe and Milligan himself.