Seixal is a Portuguese city and municipality, located in the district of Setúbal, in the metropolitan area of Lisbon. Its population includes 184,269 inhabitants (2011), in an area of 93.58 square kilometres (36.13 sq mi) that includes six parishes. It is situated across the Tagus River estuary from Lisbon. Its seat is the city of Seixal, a centre of 31,600 inhabitants situated along the Rio Judeu.

Lisbon Region is one of the seven NUTS II designated regions of Portugal, which coincides with the NUTS III subregion Lisbon Metropolitan Area. The region covers an area of 3001.95 km2 and includes a population of 2,815,851 inhabitants according to the 2011 census, a density of 1039 inhabitants/km2.