"Mary Jane" is a song by American funk singer Rick James. It was released in 1978 as the second single from his debut album Come Get It!. The song peaked in the top five on the R%26B charts in the United States in 1978. As one of his earliest hits as a solo artist, it is one of his most notable songs. It was composed by James, along with keyboardist Billy Nunn, who was credited for the keyboards, strings, background vocals, helping to compose the song, arranging flute parts, and other instrumentation work.