In the United Kingdom, the term military police refers to the three branches of service police, responsible for policing armed forces personnel. The Royal Military Police polices the British Army, the Royal Navy Police polices the Royal Navy, and the Royal Air Force Police polices the Royal Air Force. There are also a number of civilian police forces whose role is to police parts of the Defence Estate, in the UK and overseas, such as the Ministry of Defence Police, but such forces are not considered military police.

Service police

In the UK, service police are the formations of the British Armed Forces responsible for policing armed forces personnel. Each of the services has its own service police branch, a standalone unit responsible for policing, close protection of VIPs and, in the case of the Royal Military Police and Royal Air Force Police, other matters such as traffic control. The Special Investigation Branch is the name given to the detective branches of all three Service police arms: the Royal Navy Police, Royal Military Police and Royal Air Force Police. In December 2022 the separate SIBs were amalgamated into a single joint service unit called Defence Serious Crime Unit (DSCU).

Civilian police forces

There are several civil police forces responsible to the Ministry of Defence. They each have specific roles and are staffed by police officers who are not part of the armed forces and have the powers of a constable.