Gerald Rydel Simpson (born 16 February 1967, Moss Side, Manchester, England), better known as A Guy Called Gerald, is a British musician, record producer and DJ.

He is best known for his early work in the Manchester acid house scene in the late 1980s and the track "Voodoo Ray". At that time, he specialised in techno music produced using equipment such as the Roland TB-303 bass synthesiser and the TR-808 drum machine.