Pope Celestine V (Latin: Caelestinus V; 1215 – 19 May 1296), born Pietro Angelerio (according to some sources Angelario, Angelieri, Angelliero, or Angeleri), also known as Pietro da Morrone and Peter of Morrone, is Pope for five months from July 5 to December 13, 1294, when he resigns.

He is also a monk and hermit who founds the order of the Celestines.

He is elected Pope in the Catholic Church's last non-conclave papal election ending a two-year impasse.

Among the only surviving edicts he issues is confirmation of the right of the Pope to abdicate; nearly all of his other official acts ware annulled by his successor, Boniface VIII.

A week after issuing the decree, Celestine resigns, stating his desire to return to his humble, pre-papal life.

On December 13, 1294, Celestine announces his resignation.

Celestine V is subsequently imprisoned by Pope Boniface VIII, in the castle of Fumone in the Campagna region, where he dies on May 19, 1296 at the age of 81.

In 1313, Celestine V is canonized.

No subsequent Pope has taken the name "Celestine".