Piero di Cosimo (2 January 1462 – 12 April 1522), also known as Piero di Lorenzo, was a Florentine painter of the Italian Renaissance.

He is most famous for the mythological and allegorical subjects he painted in the late Quattrocento; he is said to have abandoned these to return to religious subjects under the influence of Savonarola, the preacher who exercised a huge sway in Florence in the 1490s, and had a similar effect on Botticelli. The High Renaissance style of the new century had little influence on him, and he retained the straightforward realism of his figures, which combines with an often whimsical treatment of his subjects to create the distinctive mood of his works. Vasari has many stories of his eccentricity, and the mythological subjects have an individual and quirky fascination.