Billy Stewart (March 24, 1937 – January 17, 1970) was an American musical artist, with a highly distinctive scat-singing style, who enjoyed popularity in the early 1960s. Billy Stewart began singing publicly with his mother's group, the Stewart Gospel Singers, as a teenager. He made the transition to secular music by filling in occasionally for the Rainbows, a D.C. area vocal group led by future soul star Don Covay. It was also through the Rainbows that Stewart met another aspiring singer, a very young Marvin Gaye.