* He founded the Platonic Academy in Florence. The Medici Academy in Florence was founded by Cosimo de' Medici to serve as a center of Humanist studies and Neoplatonic philosophy. It was led by Marsilio Ficino and attracted scholars like Pico della Mirandola, Cristoforo Landino, and Angelo Poliziano.
* He was a patron of architecture, sculpture, and painting. Many famous artists of the time worked under his patronage in Florence, including Brunelleschi, Donatello, and Fra Angelico.
- Filippo Brunelleschi, the architect who built the dome of the Florence Cathedral, was commissioned by Cosimo to design the Pazzi Chapel in the church of Santa Croce in Florence.
- Donatello , a sculptor, who created the bronze David, was also a beneficiary of Cosimo's patronage.
-Fra Angelico, whose paintings are known for their beauty and spirituality, was a Dominican friar who worked under Cosimo's patronage. Cosimo commissioned Fra Angelico to paint frescoes in the San Marco convent in Florence.
* He established a library in Florence. Cosimo collected manuscripts from across the ancient world. Many of these manuscripts formed the basis of the Laurentian Library, which became one of the world's most important libraries.
* He was a major patron of humanistic scholarship. Cosimo supported scholars who studied the ancient Greek and Roman classics, and he helped to establish a new, more secular form of education.
* He helped to establish Medici hegemony in Florence, which allowed for cultural and artistic developments of the Renaissance to flower in Florence.