The PSP (Polícia de Segurança Pública) is Portugal's national civilian police force, founded in 1867. Responsible for defending Republican democracy and safeguarding internal security and citizens' rights, the PSP polices major cities—Lisbon, Porto, Faro—and large urban areas, covering only 4% of Portugal's territory but roughly half the population. Led by a National Director under the Ministry of Internal Affairs, its approximately 21,500 officers handle preventive policing, crime investigation, public order, airport security, diplomatic protection, private security regulation, firearms licensing, and border control (since 2023).​

PSP vs. GNR: The PSP is civilian with police-focused training and urban jurisdiction, while the GNR (Guarda Nacional Republicana) is military (gendarmerie) with military training, covering 96% of Portugal's rural and suburban territory. Both share core public safety missions but differ fundamentally in nature, training, and geographic responsibility.