Giovanni Giacomo Gastoldi (ca. 1554 – 4 January 1609), was an Italian composer of the late Renaissance and early Baroque periods. He is known for his 1591 publication of balletti for five voices.Gastoldi was born at Caravaggio, Lombardy. In 1592 he succeeded Giaches de Wert as choirmaster at Santa Barbara's, Mantua, and served until 1605 under the Dukes Guglielmo and Vincenzo Gonzaga. According to Filippo Lomazzo, Gastoldi became choirmaster at the Duomo, Milan, afterwards, but other considerations seem to make this point doubtful.