Urduliz () is a municipality located in northern Biscay, Spain. While connected to Greater Bilbao both by the Bilbao metro and BizkaiBus, the municipality is part of Mungialdea. The municipality shows a mixture of industrial and rural qualities, being divided in three separate villages or neighborhoods. According to the 2024 census, it has 5,626 inhabitants.
Located in the region of Uribe Kosta, Urduliz sits in the Butron river valley, which has a northwestâÂÂsoutheast orientation. The southeast edge of the valley is bounded by a ridge (Las Peñas de Santa Marina). This ridge contains ruins of a portion of Bilbao's iron ring, cliffs with rock climbing routes, and the hermitage of Saint Marina.