Paolo Agostino (or Agostini; Augustinus in Latin; c. 1583 – 1629) was an Italian composer and organist of the early Baroque era. He was born perhaps at Vallerano, near Viterbo. He studied under Giovanni Bernardino Nanino, according to the dedication in the third and fourth books of his masses. Subsequently, he married Nanino's daughter.
He held a series of positions as organist and maestro di cappella (choirmaster) between 1607 and 1626, when he succeeded Vincenzo Ugolini as maestro of the Cappella Giulia's choir in St. Peter's Basilica.