The only leap year baby to become pope was Paul 111, who was born in Italy on this in 1468. The former Alessandro Farnese became pope in 1534. He convened the Council of Trent in 1545. He was a significant patron of the arts, and commissioned Michelangelo to paint the Last Judgement on the wall of the Sistine Chapel.
Pope Paul 111 died in 1549. He is buried in a tomb which Michelangelo designed.
The scientist Nicolaus Copernicus dedicated his work, De revolutionbus orbium coelestium (On the Revolutions of the Celestial Spheres), to Pope Paul 111.
source: The Little Black Book