Portugal is a democratic republic ruled by the constitution of 1976 with Lisbon, the nation's largest city, as its capital. The four main governing components are the president of the republic, the assembly of the republic, the government, and the courts. The constitution grants the division or separation of powers among legislative, executive, and judicial branches. Portugal like most European countries has no state religion, making it a secular state.

Portugal is a democratic republic ruled by the constitution of 1976 with Lisbon, the nation's largest city, as its capital. The four main governing components are the president of the republic, the assembly of the republic, the government, and the courts. The constitution grants the division or separation of powers among legislative, executive, and judicial branches. Portugal like most European countries has no state religion, making it a secular state.

The president, who is elected to a five-year term, has a supervising, nonexecutive role. The current President is Aníbal Cavaco Silva. The Assembly of the Republic is a unicameral parliament composed of 230 deputies elected for four-year terms.

The government is headed by the prime minister (currently José Sócrates), who chooses the Council of Ministers, comprising all the ministers and the respective state secretaries. The national and regional governments, and the Portuguese parliament, are dominated by two political parties, the Socialist Party and the Social Democratic Party. Minority parties CDU (Portuguese Communist Party plus Ecologist Party "The Greens"), Bloco de Esquerda (Left Bloc) and CDS-PP (People's Party) are also represented in the parliament and local governments.

The courts are organized into categories, including judicial, administrative, and fiscal. The supreme courts are the courts of last appeal. A thirteen-member constitutional court oversees the constitutionality of legislation.