Del Marquis (born Derek Gruen in New York) is the lead guitarist for the group Scissor Sisters - and one of three gay band members.
He was introduced to the band at the insistence his best friend, David Russell, who was dating lead singer Jake Shears at the time. He originally hated the band when he first saw them perform in a gay bar named 'The Cock'. His current membership of the band is due to his reappraisal of their music when he next came across them some months later, and subsequent reply to an advertisement the band had placed in a newspaper for a guitarist. According to his own account on the band DVD, he has stalked several renowned guitarists, sometimes sleeping outside the hotels they were sleeping in. One of these was Robert Smith of The Cure.
Unlike the outrageously flamboyant stage image of Jake Shears and Ana Matronic, his fellow band members, Del possesses a slightly more subdued image on stage, although still has a recognisable style of his own. He has a keen interest in graphic design and film, is known as an advocate for civil rights and 'liberation concepts', and possesses an unofficial fan group who call themselves the Deltoids, with whom he has a relatively good relationship.