Law enforcement in Spain is carried out by numerous organizations.

The Guardia Civil is the national gendarmerie force and has military status. It patrols the entire national territory except for those areas that belong to the National Police; enforces customs duties and investigates crimes.

The Policía Nacional has civilian status and deals with criminal offences and public order in big towns and cities. It includes special anti-riot units.

The Policía Municipal operates in most cities and important towns, concentrating on preventing crime, settling minor incidents, traffic control, and, crucially, intelligence gathering.

There are autonomous police forces, under the rule of the regional governments, . They are the Mossos d'Esquadra in Catalonia, the Ertzaintza in the Basque Country, and the Policía Foral in Navarre.

The duties of the Customs Surveillance Service include policing contraband, illegal drugs and money laundering.