Gustavus Waltz (fl. 1732-1759) was a German bass opera singer who collaborated with Handel.
Like Handel himself, Waltz was a naturalized Englishman, originally German, and is said to have worked for Handel as a cook. Their collaboration began in 1732. Waltz was a choral singer as well as a soloist.
Waltz created roles in Arianna in Creta, Ariodante, Alcina, and Atalanta. He sang in the chorus for the last time in a 1754 performance of (The Messiah Foundling Hospital).