Giuliano de' Medici (1478/1479–March, 1516), created Duke of Nemours in 1515, was one of three sons of Lorenzo the Magnificent: Piero, Giovanni and Giuliano.

His older brother Piero was briefly the ruler of Florence after Lorenzo's death, until the republican faction drove out the Medici in 1494. After the Holy League, headed by Spain, drove from Italy the French forces that had supported the Florentine republicans, the Medici family were restored to power. Giuliano reigned at Florence from 1512 to 1516.

He married Philiberta (1498–1524), a princess of the House of Savoy, in February 1515, at the court of France. Francis I of France invested them jointly with the Nemours title (which had recently reverted once again to the French crown) on the occasion, and was apparently grooming him for the throne of Naples (in which the French maintained a historical interest) when Giuliano died prematurely. He was followed at Florence by his nephew Lorenzo.

Giuliano left a single illegitimate son, Ippolito de' Medici.

His portrait, painted in Rome by Raphael (a painter favored by Leo), shows Rome's Castel Sant'Angelo behind a curtain. (A studio version is at the Metropolitan Museum.)

Giuliano's tomb in the Medici Chapel in the Church of San Lorenzo, Florence, is ornamented with the Night and Day of Michelangelo, along with a statue of Giuliano by Michelangelo. Due to the identical common name (Giuliano de' Medici) which he shares with his uncle, whose tomb is also in the Medici chapel, his tomb is often mistaken for that of his uncle.