Fermin Muguruza (born 20 April 1963 in Irun, Basque Country, Spain) is a Basque rock musician, singer, songwriter, producer, record label manager, and co-founder for the ska punk band Kortatu, active from 1983 to 1988, and for the crossover group Negu Gorriak, active from 1990 to 1996.

He is the brother of musicians Íñigo Muguruza and Jabier Muguruza and is one of the personalities interviewed for the documentary film The Basque Ball, released in 2003.