The European Parliament is the directly elected legislative body of the European Union, with 720 members (MEPs) elected every five years by citizens of all 27 member states. Portugal elects 21 MEPs through proportional representation.

The Parliament co-legislates with the Council of the EU on most EU law, approves the EU budget, and scrutinizes EU institutions including the European Commission. Its decisions affect Portuguese citizens through EU regulations on trade, agriculture, environmental standards, consumer protection, digital markets, and more.

Portuguese MEPs sit in European political groups aligned with their domestic parties — for example, PS MEPs in the Socialists & Democrats (S&D), PSD/CDS in the European People's Party (EPP), and Chega in the Patriots for Europe group. Key committees where Portuguese interests feature prominently include fisheries, cohesion policy, and economic affairs.