Guy Anthony O'Brien (born June 15, 1962), known by his stage name Master Gee, is an American hip hop recording artist and DJ.

On the band's signature song, "Rapper's Delight", he raps, "I said M-A-S, T-E-R, a G with a double E, I said I go by the unforgettable name of the man they call the Master Gee".

O'Brien grew up in Teaneck, New Jersey, where at an early age he was exposed to a steady stream of doo wop and rhythm and blues, and established himself as an energetic emcee in the pioneering Phase 2 hip-hop crew.

[1] During the early infancy of the commercial hip-hop movement in 1979, Master Gee, Big Bank Hank and Wonder Mike were discovered by producer Sylvia Robinson[2] and brought together to form The Sugarhill Gang.

[5] In 2014, name usage was amicably resolved, and Master Gee has since re-emerged as a mainstay in the hip hop community and music industry.