Bilbao or Bilbo is a city in northern Spain, the largest city in the province of Biscay and in the autonomous community of the Basque Country. With a population of 347,342 as of 2024, it is the 11th most populous city in Spain, and the most populous in northern Spain. The Bilbao metropolitan area has 1,037,847 inhabitants, making it the most populous metropolitan area in northern Spain. The comarca of Greater Bilbao is the fifth-largest urban area in Spain. Bilbao is also the main urban area in what is defined as the Greater Basque region.
Bilbao is located in the north-central part of Spain, some 16 kilometres (10 mi) south of the Bay of Biscay, where the economic social development is located, where the estuary of Bilbao is formed.