Filippo Sega was a Catholic bishop from 1575 to 1596 and a cardinal from 1591 to 1596. He served as a papal diplomat in several important and sensitive posts, in Flanders, Spain, Vienna, Prague, and F

He was born at Sermoneta, in the Papal States, as the second son of Bonifacio, lord of Sermoneta, and Caterina di Alberto Pio, daughter of the lord of Carpi. He was the nephew of Cardinal Niccolò Caet