Andrea was born Andrea d'Agnolo di Francesco di Luca di Paolo del Migliore in Florence on 16 July 1486. Since his father, Agnolo, was a tailor (sarto), he became known as "del Sarto" ("tailor's son").[1] Since 1677 some have attributed the surname Vannucchi with little documentation. By 1494 Andrea was apprenticed to a goldsmith, and then to a woodcarver and painter named Gian Barile, with whom he remained until 1498. According to Vasari, he then apprenticed to Piero di Cosimo, and later with Raffaellino del Garbo (Carli).
Andrea and an older friend Franciabigio decided to open a joint studio at a lodging together in the Piazza del Grano. The first product of their partnership may have been the Baptism of Christ for the Florentine Compagnia dello Scalzo, the beginning of a monochrome fresco series. By the time the partnership was dissolved, Sarto's style bore the stamp of individuality. It "is marked throughout his career by an interest, exceptional among Florentines, in effects of colour and atmosphere and by sophisticated informality and natural expression of emotion.