John Le Mesurier was an English actor. He is probably best remembered for his comedic role as Sergeant Arthur Wilson in the BBC television situation comedy Dad's Army (1968–1977). A self-confessed "jobbing actor", Le Mesurier appeared in more than 120 films across a range of genres, normally in smaller supporting parts.

Le Mesurier was born John Elton Le Mesurier Halliley, in Bedford on 5 April 1912. His parents were Charles Elton Halliley, a solicitor, and Amy Michelle (née Le Mesurier), whose family were from Alderney in the Channel Islands; both families were affluent, with histories of government service or work in the legal profession. While John was an infant the family settled in Bury St Edmunds, in West Suffolk. He was sent to school, first to Grenham House in Kent, and later to Sherborne School in Dorset, where one of his fellow pupils was the mathematician Alan Turing.