Alfons or Alfonso III of Aragon (1265 - June 18, 1291, also Alfons II of Barcelona), surnamed the Liberal, was the king of Aragon and count of Barcelona from 1285 to 1291. He was a son of Peter III of Aragon.

He conquered the island of Minorca in 1287.

His inability to resist the demands of his nobles left a heritage of trouble in Aragon. By recognising their right to rebel in the articles called the Union he helped to make anarchy permanent.

For this reason, probably, Dante, in the Divine Comedy, recounts that he saw Alfonso's spirit seated outside the gates of Purgatory with the other monarchs whom Dante blamed for the chaotic political state of Europe during the 13th century.