The House of Chigi (IPA: [ˈkiːdʒi]) is an Italian princely family of Sienese origin descended from the counts of Ardenghesca,[2] which possessed castles in the Maremma, southern Tuscany.

[2] He became an immensely rich banker, and built the palace and gardens afterwards known as the Farnesina, decorated by Raphael, Sebastiano del Piombo, Giulio Romano, and Il Sodoma, and was noted for the splendour of his entertainments.

Pope Julius II made him practically his finance minister and gave him the privilege of quartering his own (Della Rovere) arms with those of the Chigi.

Prince Sigismondo's brother, Flavio III (1810–1885), became a Cardinal on December 22, 1873 with the title of Santa Maria del Popolo; he had been Nuncio to France in the 1860s.

Prince Mario Chigi Albani della Rovere succeeded his father in 1877 and served as Marshal of the Holy Roman Church at the Conclave of 1878.

He had one son, Don Agostino Chigi Albani della Rovere (1929–2002) and one daughter, Princess Francesca, with his wife, Marian Berry, an American heiress.

The family's mausoleum is in the Chigi Chapel of the Basilica of Santa Maria del Popolo in Rome, the work of Raphael and Gian Lorenzo Bernini.