Flavio Orsini (1532 – 16 May 1581) was a cardinal of the Catholic Church. He was a member of the Orsini family.
Born in Rome, he became bishop of Muro Lucano, and later moved to bishop of Spoleto. He took part in the Roman Curia.
He was made a cardinal on 12 March 1565 by Pope Pius IV.
Flavio Orsini died in Pozzuoli, near Naples.