Election of Urban II as the 159th Pope of the Catholic Church. He is best known for initiating the Crusades.

The 1088 papal election subsequent to the death of Pope Victor III in 1087 was held on 12 March 1088. Six cardinal-bishops, assisted by two lower-ranking cardinals, elected Cardinal-Bishop of Ostia Odon de Lagery as the new Pope. He assumed the name Urban II.

Pope Urban II, otherwise known as Odo of Châtillon or Otho de Lagery, was the head of the Catholic Church and ruler of the Papal States from 12 March 1088 to his death. He is best known for convening the Council of Clermont, which ignited the series of Christian military expeditions known as the Crusades.

This chronological list of the popes of the Catholic Church corresponds to that given in the Annuario Pontificio under the heading "I Sommi Pontefici Romani", excluding those that are explicitly indicated as antipopes. Published every year by the Roman Curia, the Annuario Pontificio no longer identifies popes by regnal number, stating that it is impossible to decide which pope represented the legitimate succession at various times. The 2001 edition of the Annuario Pontificio introduced "almost 200 corrections to its existing biographies of the popes, from St Peter to John Paul II". The corrections concerned dates, especially in the first two centuries, birthplaces and the family name of one pope.

The pope is the bishop of Rome and the visible head of the worldwide Catholic Church. He is also known as the supreme pontiff, Roman pontiff, or sovereign pontiff. From the 8th century until 1870, the pope was the sovereign or head of state of the Papal States, and since 1929 of the much smaller Vatican City state. From a Catholic viewpoint, the primacy of the bishop of Rome is largely derived from his role as the apostolic successor to Saint Peter, to whom primacy was conferred by Jesus, who gave Peter the Keys of Heaven and the powers of "binding and loosing", naming him as the "rock" upon which the Church would be built. The current pope is Leo XIV, who was elected on 8 May 2025 on the second day of the 2025 papal conclave.