Law enforcement in the Republic of Ireland is the responsibility of Ireland's civilian police force, theGarda Síochána, commonly referred to as theGardaí orthe Guards. It is responsible for all civil policing within the country and has been the only territorial police force since their merger with theDublin Metropolitan Police in 1925.

The Garda Síochána are responsible for national and local policing in Ireland. The service is headed by theGarda Commissioner who is appointed by theGovernment of Ireland. Its headquarters are located inPhoenix Park inDublin.
TheGarda Síochána Reserve is the volunteer reserve section of the Gardaí. Its purpose is to supplement the work of members of the Garda Síochána in performing its functions.[1]
TheMilitary Police Corps is the corps of theIrish Army responsible for the provision ofpolicing service personnel and providing amilitary police presence to forces while on exercise and deployment. Its tasks increase during wartime to include traffic control organisation andPOW andrefugee control. The Military Police Corps are distinguished from other units by their wearing of a red beret.
The Military Police Corps enjoy a close working relationship with theGarda Síochána at both national and local levels, with the Gardaí providing specialist training to the Corps incriminal investigation.
WithinDublin Airport,Cork Airport, andShannon Airport, theAirport Police Service perform aviation security functions. They are employed byDublin Airport Authority and authorised by theMinister for Transport, Tourism and Sport.
WithinDublin Port andDún Laoghaire Harbour, theDublin Harbour Police and theDún Laoghaire Harbour Police (operated by theDublin Port Company &Dún Laoghaire harbour company respectively) perform a similar role to theAirport Police Service.
The powers of these organisations are limited to the airport/port buildings and grounds.[2][3]
TheSpecial Detective Unit (SDU) is a unit of theGarda Síochána under itsCrime & Security Branch (CSB).[4] Their responsibilities includecounter-terrorism,[5]counter-espionage, providing an armed response to incidents, protection of the State, protection of cash shipments, monitoring the activities of subversive and extremist groups, protection of VIPs and operation of the Witness Security Program.[4]
TheOffice of the Revenue Commissioners operate a customs service at all major ports of entry to Ireland and are mandated to stop allillegal narcotics and firearms from entering the state. Authorised officers have a wide range of powers including arrest under theCustoms Consolidation Act 1876 (39 & 40 Vict. c. 36) and theFinance Act 2005.[6][7] They are also authorised to investigate revenue offences under theTaxes Consolidation Act 1997.[8]