List of defunct law enforcement agencies in the United Kingdom

See List of law enforcement agencies in the United Kingdom, Crown Dependencies and British Overseas Territories for these.

The gradual process of amalgamation culminated with the creation of a single Police Service of Scotland in 2013.

The Local Government (Scotland) Act 1929 merged two pairs of county constabularies.

The Local Government (Scotland) Act 1973 created new police forces based on the new regions and island areas from 16 May 1975.

From the archives of the British Transport Police: Merged to form the Admiralty Constabulary in 1949.

Borough of Newcastle-under-Lyme Police hat badge, in the collection of the Staffordshire County Museum and displayed at the Shire Hall, Stafford