Mario Gray, known professionally as Rio West, is an American rapper, songwriter, record producer, videographer, and media personality. Since his debut in 2012 with the mixtape Substance, Rio West has been widely regarded as one of the most technically skilled emcees in the hip hop underground circuit. Aside from his solo career, he is also known as a member of the hip hop group HMESquad alongside his Herd Mics Entertainment (HME) label-mates, Chris Hussle, LX(Xplainluxury), Ave-E-neW, and Voice of a Gemini.