Leioa (Spanish: Lejona) is a municipality in Biscay, Basque Country, in northern Spain.

The Udondo river constitutes the eastern limit of the municipality.

The municipality of Leioa still retains much of its agricultural past and out of the urban centre many traditional Basque houses can still be seen on little family farms, though rapid development puts their long-term future in question.

The University of the Basque Country (EHU-UPV Euskal Herriko Unibertsitatea - Universidad del Pais Vasco) has most faculties within this municipality.

This article about a location in the Basque Country, Spain, is a stub.