The Flying Squad is a branch of London's Metropolitan Police force. It was formed in 1919 as the "Mobile Patrol Experiment", a branch of the Criminal Investigation Department (CID), in response to a crime wave that followed the end of World War I. Its officers were originally nicknamed the "thief takers". It consists of police officers trained in high-speed driving, whose task is to detect and prevent armed robbery and similar crimes. The name reflects the fact that the officers operate across the boundaries of London's police divisions. In 1978 it was renamed the "Central Robbery Squad". Its most popular nicknames are "the Sweeney" (Cockney rhyming slang for "Sweeney Todd"/"Flying Squad") and "The Heavy Mob".

The squad's work was dramatized in the 1970s British television series The Sweeney. This was the era in which the Sweeney's close ties with the criminal underworld, which had always been a necessary part of its strategy, were being exposed to public criticism. A number of scandals involving bribery and corruption were revealed, and on 7 July 1977, the squad's commander, Detective Chief Superintendent Kenneth Drury, was convicted of five counts of corruption and jailed for eight years. Twelve other officers were also convicted and many more resigned. These and other scandals lead to a massive internal investigation by the Dorset Constabulary into the Metropolitan Police Service and the City of London Police – code named Operation Countryman.

The squad now forms part of the Serious and Organised Crime Group of the Specialist Crime Directorate.