Leonardo is the Teenage Mutant Ninja Turtles character named after Leonardo da Vinci.
The four turtles are named after Italian Renaissance artists: Leonardo, Donatello, Raphael, and Michelangelo. Leonardo da Vinci is especially famous for works such as the Mona Lisa and The Last Supper, as well as notebooks filled with studies of anatomy, engineering, and natural phenomena.
The naming idea began as a playful contrast between serious historical artists and a team of mutant sewer turtles. It also gave the creators a memorable way to distinguish the brothers while reinforcing the comic’s unusual mixture of high culture, martial arts, and parody.
Leonardo’s character traits do not directly reproduce da Vinci’s biography. The Turtle is primarily a disciplined ninja leader who uses twin swords. The shared name is an homage, not a claim that the fictional hero is based on the historical artist’s life.