Zumarraga is a municipality and industrial town located in the Gipuzkoa province within the Basque Country autonomous community of northern Spain. It is situated approximately 35 miles (56 km) southwest of San Sebastián and 10 miles (16 km) northwest of Idiazabal. The Urola river flows through the vicinity of the town.
As of 2018, the municipality had a population of 9,834 people. The town is notable as the birthplace of Miguel López de Legazpi, a conquistador who explored the East Indies and the Pacific Islands, as well as Iñaki Urdangarín, the husband of Infanta Cristina of Spain.