Санта-Кроче-ин-Джерусалемме
Due to his firm and determined nature, and many enemies, Litta was not quickly named Cardinal. He was appointed Cardinal in pectore on 14 June 1664 and formally appointed Cardinal Priest of Santa Croce in Gerusalemme on 15 February 1666. He participated in the Conclaves of 1667, 1669 and 1676.