The RZA (pronounced Rizza, born Robert Diggs) is an American producer, rapper and the de facto leader of the hip-hop group Wu-Tang Clan. He was also a member of the group Gravediggaz. As well as producing almost all of the Wu-Tang's albums, he has also produced many of their solo and affiliate projects, as well as releasing a succession of solo albums (three under the alter-ego Bobby Digital) and composing several film scores, including pieces for both the Kill Bill soundtracks, as well as creating the soundtrack for the programme Afro Samurai and featuring in the film American Gangster as Detective Moses Jones.

Prior to Kill Bill, he worked on the soundtrack for Ghost Dog: Way of the Samurai, directed by Jim Jarmusch. The RZA appeared in this movie as a fellow assassin. RZA later appeared in Jarmusch's Coffee and Cigarettes as himself. He also made the soundtrack for Spike TV's anime series Afro Samurai.