Pope Benedict XII (Latin: Benedictus XII, Italian: Benedetto XII, French: Benoît XII; 1285 – 25 April 1342), born Jacques Fournier, was a cardinal and inquisitor, and later, head of the Catholic Church from 30 December 1334 to his death, in April 1342. He was the third Avignon pope and reformed monastic orders and opposed nepotism. Unable to remove his capital to Rome or Bologna, Benedict started the great palace at Avignon. He settled the beatific vision controversy of Pope John XXII with the bull Benedictus Deus, which stated that souls may attain the "fullness of the beatific vision" before the Last Judgment. Despite many diplomatic attempts with Emperor Louis IV to resolve their differences, Benedict failed to bring the Holy Roman Empire back under papal dominance. He died 25 April 1342 and was buried in Avignon.

Jacques Fournier was born in Saverdun in the County of Foix around 1285. He joined the Cistercian Order and studied at the Collège des Bernardins at the University of Paris. In 1311 he was made Abbot of Fontfroide Abbey and quickly became known for his intelligence and organisational ability.

In 1317, Jacques was made Bishop of Pamiers. It was here he undertook rigorous measures against Cathars, assisting Bernard Gui in some investigations. Fournier's investigation captured Guillaume Bélibaste, who was burned at the stake in 1321. Motivated by Philip V's edict against lepers, Jacques also investigated the supposed leper water-poisoning conspiracy and tortured the director of the Pamiers leprosarium, Guillaume Agasse, into giving a confession to the charges.

His efforts against the Cathars of Montaillou in the Ariège were carefully recorded in the Fournier Register, which he took to Rome and deposited in the Vatican Library. His transcription was edited by Jean Duvernoy and has been documented by Emmanuel Le Roy Ladurie's pioneering microhistory, Montaillou, village occitan.

In 1326, upon the successful rooting out of the last – it was believed – Cathars of the south, Jacques was made Bishop of Mirepoix in the Ariège, and, a year later, in 1327, he was made a cardinal.

Upon his elevation to cardinal, Jacques continued to wear his Cistercian cowl, which garnered him the nickname the "white cardinal". He often advised Pope John XXII on doctrinal matters, which included the heretical nature of magic. Jacques was tasked by the pope with examining the works of Peter John Olivi, Meister Eckhart, William of Ockham and Michael of Cesena.

The Conclave opened on 13 December 1334, and it appeared that there might be a quick election. A two-thirds majority were prepared to elect Cardinal Jean-Raymond de Comminges, the Bishop of Porto, if he would only swear in advance to agree not to return the papacy to Rome. Comminges refused to make any promises in order to get elected. The Conclave therefore proposed Jacques Fournier's name, almost as a dare. Owing to his inexperience in politics, it was believed he would not get the votes. Upon Jacques' election the conclave was astonished, while Jacques stated, "You have elected an ignoramus". Jacques Fournier took the name of Benedict XII as the pope on 8 January 1335.

From the beginning of his pontificate, Benedict worked to reform the Curia and secular clergy in an effort to curb clerical avarice and nepotism as well as abuses in the granting of benefices. However, the religious orders were the primary target of his major reform efforts. By 1335–1336, Benedict had enacted changes that are viewed as one of the milestones of his pontificate.