Gustavus Waltz (fl. 1732–1759) was a German bass opera singer. Basing himself in England from 1732, he collaborated with Handel from 1733 when he appeared in La Semiramide riconosciuta, an opera pasticcio. Like Handel, Waltz took British nationality.[citation needed].
Waltz created roles in the oratorio Athalia (1733); and in the operas Arianna in Creta (1734), Ariodante (1735), Alcina (1735), and Atalanta (1736). As well as being a soloist, he sang in the chorus (for the last time in a 1754 performance of Messiah at the Foundling Hospital). He also taught singing: his students included Isabella Young.