The 1378 papal conclave which was held from April 7 to 9, 1378, was the papal conclave which was the immediate cause of the Western Schism in the Catholic Church. The conclave was one of the shortest in the history of the Catholic Church. The conclave was also the first since 1159 held in the Vatican and in Old St. Peter's Basilica.

In the papal conclave held on 29 and 30 December 1370, after the death of Pope Urban V, Cardinal Pierre Roger de Beaufort was elected pope under the name Gregory XI. He thus became seventh and the last pope of the period of Avignon Papacy.