The 1277 papal election, convened in Viterbo after the death of Pope John XXI, was the smallest papal election since the expansion of suffrage to cardinal-priests and cardinal-deacons, with only seven cardinal electors. Because John XXI had revoked Ubi periculum, the papal bull of Pope Gregory X establishing the papal conclave, with his own bull Licet felicis recordationis, the cardinal electors were able to take their time. After six months of deliberation, the cardinals eventually elected their most senior member Giovanni Gaetano Orsini as Pope Nicholas III. From the end of the election until Nicholas III's first consistory on March 12, 1278, the number of living cardinals—seven—was the lowest in the history of the Roman Catholic Church.

Pope Nicholas III, born Giovanni Gaetano Orsini, was head of the Catholic Church and ruler of the Papal States from 25 November 1277 to his death on 22 August 1280.