Portugalete is a town lying to the west of Bilbao in the province of Biscay in the Autonomous Community of Basque Country, northern Spain.

The town has 47,756 inhabitants (2013 census) and is part of Bilbao's metropolitan area. It is located at the mouth of the Estuary of Bilbao, on the left bank. It is the fifth-most densely populated municipality in Spain (following Mislata, L'Hospitalet de Llobregat, Benetusser, and Santa Coloma de Gramenet).

In 1300 Portugalete became the main competitor port for Bilbao, but it lost its predominant position in 1511 when the trade privileges were granted to the Port of Bilbao instead of Portugalete.

Despite its name, it is not near the Spanish border with Portugal and its name is not etymologically related with that country: it derives, instead, from a phonetic adaptation of its Basque name (Portu-Ugaldeta) to the Spanish language.

The city has the Vizcaya Bridge, a transporter bridge. The car ferry is suspended from a frame by wires attached to wheels on tracks above the cabin and moves from one side of the River Nervion to the other (Getxo) via a traction system.

This bridge was declared a World Heritage Site on 13 July 2006.