Albufeira (pronounced [alβuˈfɐjɾɐ] ^ⓘ, locally [aɫbʷˈfeɾɐ, aɫbˈfeɾɐ]), officially the City of Albufeira (Portuguese: Cidade de Albufeira), is a city and municipality of Faro District in the Algarve region of southern Portugal. The population in 2021 was 44,158, in an area of 140.66 square kilometres (54.31 square miles). The city proper had a population of 28,645 in 2021. It is 250 kilometres (160 mi) from Lisbon, close to Paderne Castle. Lagoa is 30 kilometres (19 mi) to the west, and Faro 45 kilometres (28 mi) to the southeast. A tourist destination due to its coastal conditions, Albufeira's population expands to around 300,000 in the summer and at Christmas and New Year owing to the number of hotels that includes marina facilities, golf courses, restaurants and bars.

It is unclear when the first settlements specifically formed in the region of Albufeira, although scientific research suggests origins during the pre-historic epoch, and that the town of Albufeira formed as an out-port of the maritime fishery. The primitive settlement was occupied by the Romans, who named it Baltum, introducing a centralized administrative structure and developing intense agricultural activities along with commerce. The Romans constructed aqueducts, roads and bridges, of which parts still remain.

After the fall of the Roman Empire, the region was ruled by Germanic peoples like the Visigoths. In the early 8th century, it was conquered by invading Muslims from northern Africa. The modern name originated from the Arabic word al-Buħayra (البحيرة), for the lagoon, in reference to the lagoon that formed in the lowlands. The Moors constructed strong defensive structures, making the area almost impregnable, allowing this area to remain in the hands of their forces longer than other possessions in Portugal. The development of agriculture during this period was notable, with the introduction of new techniques and plant species. The Moors used the plow and fertilizers, as well as winches for lifting the water from the wells, introducing the irrigation of fields, constructing dams and transforming uncultivated areas into gardens and orchards.

The Christian conquest of the region began at the end of the 12th century. When Afonso III of Portugal occupied the throne, most of the Algarve had already fallen into the hands of the Christians. Templar and Hospitaller Knights, military and religious orders that supported the Reconquista, assaulted many of the lands occupied by the Arabs, but were never successful in taking Albufeira. It was following the capture of Faro that the siege of Albufeira became unsupportable. Encircled by enemy forces on all sides, it fell in 1249 to the forces of Afonso III, who donated the lands to the Order of Aviz in 1250. The Moors were persecuted terribly by the victorious army, which chased the remaining forces into a cavern, known today as Cova do Xorino, situated near the southern limits of the old city. The town became part of the kingdom of Portugal and the Algarves. King D. Manuel I awarded a Charter (foral) to the Town of Albufeira on 20 August 1504 and from that day the town was governed according to the legislation in force for the rest of the country.

Albufeira was one of the towns of the Algarve most affected by natural calamities, but it was the 1755 Lisbon earthquake which caused the worst damage. The sea invaded the town with 10 metres (33 ft) waves, destroying almost all the buildings along the coast. In the town proper, only 27 residential buildings survived the natural disaster, but in states of ruin. The parochial church, an old mosque adapted by the Christians, where many of the residents sought refuge during the cataclysm, collapsed causing 227 deaths. Even following these events, the Algarve continued to experience aftershocks, until 20 August of the following year, which hindered the reconstruction under the Bishop D. Francisco Gomes de Avelar.

In 1833, during the Liberal Wars between absolutist and liberal forces, Albufeira was encircled and attacked by Remexido's soldiers: an anti-liberal, absolutist leader who was as popular as feared and damaged the village's buildings, having executed many of its inhabitants as well. After the 19th century, the community grew through the expansion of the fishery. This is why the locals annually celebrate 'Festival de Peixes', which has been tradition and serves to honor the fisheries in Albufeira that helped with the growth of the city.

In the first decades of the 20th century, the export of fish and nuts represented the largest contribution to the local economy of the municipality. The town itself had five factories employing 700-800 people, mostly wives of fishermen working in local production. Yet, between 1930 and 1960, there was a considerable decline in fortunes, resulting in the closing of many of these factories, the reduction in fishing boats along the coast and the abandonment of many of the homes. The population was reduced by half and the fishing industry became a subsistence activity, supporting local consumption only.

The town started to become a hub for tourism in the 1960s, and has grown to accommodate this since, growing out into the surrounding hills to accommodate thousands of the 5 million tourists who visit the Algarve region each year.