Cosimo II de' Medici (12 May 1590 – 28 February 1621) was Grand Duke of Tuscany from 1609 until 1621. He was the elder son of Ferdinando I de' Medici, Grand Duke of Tuscany and Christine of Lorraine. He married Maria Magdalena of Austria and had eight children. Galileo Galilei was his childhood tutor.
For the most of his eleven-year reign, he delegated the administration of Tuscany to his ministers. He is best remembered as the patron of Galileo Galilei, his childhood tutor.
He died of tuberculosis in 1621.