Pope Julius II (Latin: Iulius II; Italian: Giulio II; born Giuliano della Rovere; 5 December 1443 – 21 February 1513) was head of the Catholic Church and ruler of the Papal States from 1503 to his death in 1513. Nicknamed the Warrior Pope or the Fearsome Pope, he chose his papal name not in honour of Pope Julius I but in emulation of Julius Caesar. One of the most powerful and influential popes, Julius II was a central figure of the High Renaissance and left a significant cultural and political legacy. As a result of his policies during the Italian Wars, the Papal States remained independent and centralized, and the office of the papacy continued to be crucial, diplomatically and politically, during the entirety of the 16th century in Italy and Europe.

In 1506, Julius II established the Vatican Museums and initiated the rebuilding of the St. Peter's Basilica. The same year he organized the famous Swiss Guards for his personal protection and commanded a successful campaign in Romagna against local lords. The interests of Julius II lay also in the New World, as he ratified the Treaty of Tordesillas, establishing the first bishoprics in the Americas and beginning the catholicization of Latin America. In 1508, he commissioned the Raphael Rooms and Michelangelo's paintings in the Sistine Chapel.

Julius II was described by Machiavelli in his works as an ideal prince. Pope Julius II allowed people seeking indulgences to donate money to the Church which would be used for the construction of Saint Peter's Basilica. In his Julius Excluded from Heaven, the scholar Erasmus of Rotterdam described a Pope Julius II in the afterlife planning to storm Heaven when he is denied entry.