Francesco I de' Medici, Grand Duke of Tuscany (25 March 1541 – 19 October 1587) was the second Grand Duke of Tuscany, ruling from 1574 to 1587.

He was the son of Cosimo I de' Medici, Grand Duke of Tuscany and Eleonora di Toledo and served as regent for his father starting in 1564.

On December 18, 1565, he married Johanna of Austria (January 24, 1548 – April 10, 1578), the daughter of Ferdinand I, Holy Roman Emperor, and they had the following children:

• Eleonora (March 1, 1566 – September 9, 1611), who married Vincenzo I Gonzaga, Duke of Mantua (1582-1612).
• Romola (November 20, 1568 – December 2, 1568)
• Anna (December 31, 1569 – February 19, 1584)
• Isabella (September 30, 1571 – August 8, 1572)
• Lucrezia (November 7, 1572 – August 14, 1574)
• Maria (April 26, 1573 – July 3, 1642), who became Queen of France by her marriage to Henri IV December 27, 1612.
• Filippo (May 20, 1577 – March 29, 1568)

He married a second time to Bianca Capello. They had no children, but Francesco adopted her son Antonio (August 29, 1576 – May 2, 1621) by her first marriage.

He was despotic like his father, but whereas Cosimo had known how to maintain Florentine independence, Francesco acted more like a vassal of his father-in-law and subsequent Holy Roman Emperors. He continued the heavy taxation of his subjects in order to pay large sums to the empire.

He founded porcelain and stoneware manufacture, but these did not thrive until after his death. He continued his father's patronage of the arts, supporting artists and building the Medici Theater and the palace in the Pratolino, as well as founding the Accademia della Cruca . He was also passionately interested in chemistry and spent many hours in the laboratory.

Francesco was succeeded by his younger brother Ferdinando I de' Medici, Grand Duke of Tuscany.

There is a famous portrait of Francesco as a child by Agnolo Bronzino, which hangs in the Uffizi Gallery in Florence.