Alfonso III of Aragon (1265 - June 18, 1291), 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.

Preceded by: Peter III	King of Aragon	Succeeded by: James II
	Count of Barcelona
	King of Valencia