Esmeralda's Barn was a nightclub in Wilton Place, Knightsbridge, London, that was owned by the Kray twins from 1960 until its closure in 1963. The Krays used the club as a way of expanding their criminal activities into London's West End.

Ronald "Ronnie" Kray and Reginald "Reggie" Kray were English organised crime figures, and identical twin brothers from Haggerston, who were prominent from the late 1950s until their arrest in 1968. Their gang, known as the Firm, was based in the Bethnal Green, where the Kray twins lived. They were involved in murder, armed robbery, arson, protection rackets, gambling and assaults. At their peak in the 1960s, they gained a certain measure of celebrity status by mixing with prominent members of London society, being photographed by David Bailey and interviewed on television.