The Portuguese Navy (Portuguese: Marinha Portuguesa, also known as Marinha de Guerra Portuguesa or as Armada Portuguesa) is the naval branch of the Portuguese Armed Forces which, in cooperation and integrated with the other branches of the Portuguese military, is charged with the military defence of Portugal. The Portuguese Navy also participates in missions related with international compromises assumed by Portugal (mainly with NATO), as well as missions of civil interest. Today, the Portuguese Navy assumes a dual role capacity: Naval combat missions to assure Portugal's sovereignty and international commitments, and coast guard operations in its territorial waters and areas of influence.

Portuguese naval history is closely connected to the history of Portugal, and one can say that the Naval history is Portuguese History seen from the sea.

The first known battle of the Portuguese Navy was in 1180, during the reign of Portugal's first king, Afonso I of Portugal. The battle occurred when a Portuguese fleet commanded by the knight Fuas Roupinho defeated a Muslim fleet near Cape Espichel. He also made two incursions at Ceuta, in 1181 and 1182, and died during the last of these attempts to conquer Ceuta.