Ciro (Cyrus) is an opera in three acts and a prologue by the Italian composer Francesco Cavalli in collaboration with Andrea Mattioli. It was first performed at the Teatro San Giovanni e San Paolo, Venice on January 30, 1654. The libretto is by Giulio Cesare Sorrentino^[1][2] in a revised version by Aurelio Aureli. Sorrentino's libretto had been set the previous year by Francesco Provenzale for the royal theatre in Naples.