Peter the Hermit, also known as Little Peter, Peter of Amiens or Peter of Achères, was a Roman Catholic priest of Amiens and a key figure during the military expedition from France to Jerusalem, known as the People's Crusade. He is by some called Blessed Peter the Hermit, although he has not been beatified in the Catholic Church.

The People's Crusade was the beginning phase of the First Crusade whose objective was to retake the Holy Land, and Jerusalem in particular, from Islamic rule. In 1095 the head of the Roman Catholic Church Pope Urban II started to urge faithful Christians to undertake an armed pilgrimage to Jerusalem, the People's Crusade was conducted for roughly six months from April to October 1096. It is also known as the Peasants' Crusade, Paupers' Crusade or the Popular Crusade as it was executed by a mainly untrained peasant army prior to the main church-organized crusade. It was led primarily by Peter the Hermit with forces of Walter Sans Avoir. The peasant army of this crusade was destroyed by the forces of the Seljuk Turks under Kilij Arslan at the Battle of Civetot in northwestern Anatolia.