Lanfredini, Jacopo an Italian prelate, was born at Florence, October 26, 1670. He became civil auditor of cardinal Camerlingue in 1722, and the following year was declared domestic prelate, member of the consistorial congregation, and referendary of both signatures. Benedict XIII ordained him priest, March 16, 1727. Clement XIII, his compatriot, appointed him, in 1730, to a canonship in St. Peter's. After having been successively secretary of the congregation of the council, voter of the signature of grace, datary of the penitentiary, he was, in 1735, made cardinal, and bishop of Osimo and Cingoli, in the bounds of Ancona. He died May 16, 1741. See Hoefer, Nouv. Biog. Generale, s.v.