Camillo Massimi (20 July 1620 – 12 September 1677) was an Italian cardinal in 17th century Rome, best remembered as a major patron of Baroque artists such as Poussin, Lorrain, Velázquez, Duquesnoy, Algardi, Francesco Fontana and Cosimo Fancelli.

He started his ecclesiastical career as papal prelate at a young age and in 1651 he became cleric of the Apostolic Chamber.

Back in Italy Monsignor Camillo Massimo retired in semi-exile — from 1658 until the end of the pontificate of Pope Clement IX in 1669 - in a town called Roccasecca dei Volsci, in his 'Palazzo Baroniale'.

On 22 December 1670 Pope Clement X elevated him to Cardinal with the title of S. Maria in Domnica, which Massimo later changed to that of Sant'Eusebio.

He had copies, made by Pietro Santo Bartoli, of the illustrations of an antique edition of Virgil and drawings based on the ancient paintings found in the Tomb of the Nasonii in Rome.