The Gielgud Theatre is a West End theatre, located on Shaftesbury Avenue, at the corner of Rupert Street, in the City of Westminster, London. The house currently has 994 seats on three levels.

Shaftesbury Avenue is a major road in the West End of London, named after The 7th Earl of Shaftesbury. It runs north-easterly from Piccadilly Circus to New Oxford Street, crossing Charing Cross Road at Cambridge Circus. From Piccadilly Circus to Cambridge Circus, it is in the City of Westminster, and from Cambridge Circus to New Oxford Street, it is in the London Borough of Camden.