Gregorio Celli (1225 (purportedly) – 11 May 1343) was an Italian Roman Catholic priest and a professed member of the Order of Saint Augustine. Celli lived with the latter order in Rimini until he decided to spend the remainder of his life in deep contemplation and so moved to the region's hills where he dwelled in a cave near the Franciscans stationed there. It is claimed he was expelled from his order and became a Franciscan though there is no evidence to support this claim.