Jacquet was born in Vitré (Ille-et-Vilaine) and probably went to Italy at an early age. He was in Modena in 1519, working for the Rangoni family, and in 1525 was in Ferrara at the Este court, where he formed a close friendship with Adrian Willaert, the founder of the Venetian School. The next year he moved to Mantua, where he spent the rest of his life. He became "maestro di cappella" at the cathedral of Saints Peter and Paul, where his employer was Cardinal Ercole Gonzaga, the Bishop of Mantua. Cardinal Ercole Gonzaga was fond of Jacquet, and the relationship was mutually beneficial; when Gonzaga became the president of the Council of Trent, and the most enthusiastic supporter of the Counter-Reformation, he was a forceful advocate for the music of his favorite composer.