Fermin Muguruza 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.

Kortatu was a Basque ska punk band from the Basque Autonomous Community formed in Irun in the summer of 1984.