Before filming Austin Powers: The Spy Who Shagged Me (1999), Michael York advised Mike Myers to watch Smashing Time (1967) to get a feel for the Swinging Sixties.
According to his memoir, this film was the source material and ironic inspiration for Elvis Costello's song "(I Don't Want to Go to) Chelsea".
Several of the characters (Tom Wabe, Charlotte Brillig, Mrs. Gimble, Bobby Mome-Rath and Jeremy Tove) have surnames which are taken from the Lewis Carroll poem "Jabberwocky". The name of the band "The Snarks" is a reference to Carroll's poem "The Hunting of the Snark".
Homosexuality had been decriminalized in England and Wales in July 1967. This film, released in December of the same year, was one of the first major releases subsequently to feature overtly gay characters.