Girolamo Cavazzoni (1520 — post-1577), also known as "Hieronimo Cavazzoni" and nicknamed "d'Urbino," was an Italian Renaissance composer and organist, son of Marco Antonio Cavazzoni. He wrote organ masses, hymns, and ricercari, credited with the earliest canzoni. Girolamo served as the organist Chiesa di Santa Barbara, Mantova, a cathedral erected by Duca Guglielmo Gonzaga, and assisted renowned organ builder Graziadio Antegnati (1525—ca.1590) at constructing the instrument on which he subsequently played.