Alfonso Gesualdo di Conza (20 October 1540–14 February 1603) was an Italian Cardinal starting in 1561.
He was from Naples.
His attendance at the papal conclave of 1565-1566 at the age of only 25 makes him one of the youngest Cardinals ever to participate in a papal election.He was Archbishop of Conza in 1564, Bishop of Albano in 1583, Bishop of Frascati in 1587, Bishop of Porto e Santa Rufina in 1589, Bishop of Ostia in 1591, and Archbishop of Naples in 1596.
He was a patron of Sant'Andrea della Valle in Rome, the mother church of the Theatine Order.