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.

For container ships it begins with a 1080-metre mooring, with cranes, south of a thin, rectangular, pleasure boat marina.

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.

Probably the Phoenicians were in this area in the 12th century BC and they would create a commercial port in the north margin of the River Tagus.

In AD 714, the Moors conquered Lisbon, expanding the port with their Mediterranean and Atlantic trades.