Peter III of Aragon (1239 - November 11, 1285), surnamed the Great, was the king of Aragon and Valencia and count of Barcelona from 1276 to 1285. He became Peter I of Sicily from 1276. In 1262, he married Constance, daughter and heiress of Manfred of Sicily.

Peter left Aragon to his eldest son Alfonso III of Aragon, and Sicily to his second son James I of Sicily.

Preceded by:
James I of Aragon
List of Aragonese monarchs Followed by: Alfonso III of Aragon
Monarchs of Naples and Sicily Followed by: James I of Sicily