He was born in Romagnano Sesia, the son of a painter, Raffaele Crespi, and moved to Cerano with his family some years later. In 1591 he is known to have been living in Milan.
True to the Counter-Reformation piety zealously expressed in Milanese art of his time, his paintings focus on mysteries and mystical episodes in saintly life. The crowded canvases and the angles recall Mannerism, but his paintings show an emotion that evokes common sentiments in Baroque art. Along with other artists, he completed a series of paintings (Quadroni of St. Charles) of the life of St. Charles Borromeo for the Duomo of Milan; an altarpiece with the Baptism of St. Augustine for San Marco, Milan; and a Mass of St. Gregory for the Basilica of San Vittore in Varese (1615–17). Also see the nightmarish, St. Gregory Delivers the Soul of a Monk (1617), also in San Vittore.