He was born in Molfetta. As a boy he apprenticed with a modest local painter Saverio Porta, (c1667–1725), escaping the religious career his parents had intended for him. Giaquinto followed a peripatetic career, with long sojourns in Naples, Rome (between 1723 and 1753), Turin (1733 and 1735–39), and Madrid (1753–1761).The first documented work by his hand is Christ crucified with the Madonna, Saint John Evangelist, and Magdalene commissioned in 1730 by King John V of Portugal for the basilica of the Palace of Mafra.