Giovanni Gaetano Orsini (ca.

1285 - August 27, 1335), Cardinal of the Holy Roman Church from December 17, 1316, until his death, is a Roman nobleman, a nephew of Pope Nicholas III and a grandson of Matteo Rosso Orsini.

He is sometimes recorded under the names Gian Gaetano Orsini and Giangaetano Orsini.

In 1326 the Avignon Pope John XXII sends him as his Legate a latere to Italy, at this time much troubled by civil wars, with the task of bringing peace.

In the event, Orsini finds himself embroiled in battles with the Emperor, Ludwig of Bavaria and his antipope, Nicholas V. After taking Rome and becoming Captain of the City, he pursues his own Orsini interests, however, and loses the support of the Pope.

He is dismissed as legate in 1334 and dies the next year.