Porto is one of the 22 multi-member constituencies of the Assembly of the Republic, the national legislature of Portugal. The constituency was established in 1976 when the Assembly of the Republic was established by the constitution following the restoration of democracy. It is conterminous with the district of Porto. The constituency currently elects 40 of the 230 members of the Assembly of the Republic using the closed party-list proportional representation electoral system. At the 2024 legislative election it had 1,591,760 registered electors.