天主教会大分裂（1378年－1417年），是罗马天主教会中数位教宗同时要求其合法性导致的一次分裂。和“异端”（Hérésie）不同，“分裂”（Schisme）这个称谓是被天主教会官方统一认可的。

1309年，教宗克雷芒五世被法兰西国王菲利浦四世掳到法兰西王国的亚维侬，是为亚维侬教廷。1377年，格列高利十一世（Grégoire XI）把教廷由法国亚维侬迁回意大利罗马。格列高利十一世去世后，枢机团于1378年一致选出一名意大利人为继任教宗乌尔巴诺六世（Urban VI）。但后来其中的13位枢机（大多数是法国人）宣布该选举无效，并另选出一名法国人克雷芒七世（Clément VII）为教宗。乌尔巴诺六世将克雷孟七世及其追随者处以破门律，并成立了自己的枢机团。

The Western Schism or Papal Schism was a split within the Roman Catholic Church which lasted from 1378 to 1417. Three men simultaneously claimed to be the true pope. Driven by politics rather than any theological disagreement, the schism was ended by the Council of Constance (1414–1418). For a time these rival claims to the papal throne damaged the reputation of the office. The affair is sometimes referred to as the Great Schism, although this term is typically reserved for the East–West Schism (1054) between the Western Churches answering to the See of Rome and the Orthodox Churches of the East.