Leioa is a municipality located in the province of Biscay within the Basque Country region of northern Spain. It covers an area of 8.36 square kilometres and currently serves as part of the Bilbao conurbation. As of 2019, the municipality had a population of 31,795 residents.
The geography of the municipality is defined by its proximity to neighboring towns and natural landmarks. Leioa is situated south of Getxo and Berango, while it shares borders to the east and south with Erandio, Portugalete, and Sestao. The Udondo river serves as the eastern boundary of the municipality.