Campeggio, Tommaso, an Italian prelate, was born in 1500. He was nephew of cardinal Lorenzo, and accompanied that prelate on many of his missions. He succeeded him in the episcopal see of Feltre, and was sent by Paul III as nuncio to the colloquy of Worms (1540). He was one of the three bishops present at the opening of the Council of Trent in 1545, and there assisted at the sessions held under the pontificate of Paul III. He died at Rome, Jan. 11, 1564. He wrote various treatises on ecclesiastical discipline, among which we notice, De Auctoritate Sanctorum Concilioruin, dedicated to pope Pius IV (Venice, 1561): — also various works on ecclesiastical duties. (ibid. 1550- 55). See Hoefer, Nouv. Biog. Generale, s.v.