Portimão (European Portuguese pronunciation: [puɾtiˈmɐ̃w] ^ⓘ) is a city and a municipality in the district of Faro, in the Algarve region of southern Portugal. The population in 2022 was 63,079 in an area of 182.06 km². It was formerly known as Vila Nova de Portimão. In 1924, it was incorporated as a cidade and became known merely as Portimão. Historically a fishing and shipbuilding centre, it has nonetheless developed into a strong tourist centre oriented along its beaches and southern coast. The two largest population centers in the Algarve are Portimão and Faro.

The area was settled during the prehistoric epoch: the Cynetes, influenced by the Celts and Tartessos lived in the Algarve for many centuries. In the area of Alcalar there are several remnants of Neolithic funerary sites of which only one, Alcalar monument number seven, comprising a circular chamber composed of schist stone and long corridor, remains. Comparable to western European and Irish monuments, the funeral crypt, with two lateral ritual niches, was protected by a tumulus: a similar site exists in Monte Canelas.

The mouth of the Arade River proved an important natural shelter that soon became a small commercial port for the Phoenicians, Greeks and Carthaginians. The Carthaginians founded two settlements nearby in the mid-6th century BC, known by their Roman names Portus Magonis and Portus Hannibalis ("Hannibal's Port"). The former was the nucleus of present-day Portimão.

Obvious vestiges of the Roman occupation are situated near Figueira, at Quinta da Abicada, in the confluence of two rivers, where the remains of various rooms were unearthed. Also, in the area of Coca Maravilhas was discovered a well-preserved period cistern, while along the Arade River there have been identified gold coins.

In the 5th century, the Algarve was ruled by the Visigoths until the arrival of the Moors. It was during the Moorish occupation that the settlement changed to Burj Munt. The river and its ocean access to the ancient city of Shilb (Silves), then capital of the Arabian Algarve.

Along with Silves and Alvor, the small fishing centre in Portimão was reconquered in 1249 from the Arabs by Knights of the Order of Santiago and forcibly integrated into the fledgling Kingdom of Portugal, during the reign of Afonso III of Portugal. Due to the constant raids of pirates, the coastal area of Portimão was considered unsafe to live.

Its geographic location created strong economic conditions to allow the region to prosper, eventually allowing Portimão to obtain the status of town in 1435. The inhabitants understood the necessity of constructing walls, in order to protect themselves from constant invasions. The construction of two forts, the Castle of São João (in Ferragudo) and the Fort of Santa Catarina (Portimão), protected the centre from attacks from pirates and privateers during this period.

In Portimão, a major part of the commerce was accomplished across the sea. The transport across the Arade River was done across a boat that docked at the Largo de Barca. Until bridge and road was constructed, 400 years later, it was the only form of crossing the river.