The Port of Lisbon (Portuguese: Porto de Lisboa) is the third-largest port in Portugal, mainly on the north sides of the Tagus’s large natural harbour that opens west, through a short strait, onto the Atlantic Ocean. Each part lies against central parts of the Portuguese capital Lisbon. Due to its strategic site between Europe, Africa, and the Atlantic, it is one of the most accessed and used in Europe. For container ships it begins with a 1080-metre mooring, with cranes, south of a thin, rectangular, pleasure boat marina. It is north-east of the centre of the strait-spanning suspension bridge, the Ponte 25 de Abril. Continuations are to the north-east. These are a bank-side cruise ship terminal next to the old Alfama district, followed by multi-use harbour-side terminals at Xabregas, Grilo, Beato ([ˈbjatu])) and Braço de Prata, Marvila (Lisbon).

Denser military docks are beyond a headland to the south-east – Lisbon Naval Base, long colloquially synonymous with Alfeite, a slightly wider, once royally-owned, district.