Fermin Muguruza (20 April 1963) is a Basque rock musician, singer, songwriter, producer, record label manager, and co-founder of the ska punk band Kortatu, active from 1983 to 1988, and of the crossover group Negu Gorriak, active from 1990 to 1996. 　　Born in Irun, Basque Autonomous Community, Spain, he is the brother of musicians ??igo Muguruza and Jabier Muguruza and is one of the personalities interviewed for the documentary film The Basque Ball, released in 2003.