Hugh le Despencer, 1st Baron le Despencer (1223 – 4 August 1265) was an important ally of Simon de Montfort during the reign of Henry III. He served briefly as Justiciar of England in 1260 and as Constable of the Tower of London. Hugh Le Despenser, chief justiciar of England, first played an important part in 1258, when he was prominent on the baronial side in the Mad Parliament of Oxford. In 1260 the barons chose him to succeed Hugh Bigod as Justiciar, and in 1263 the king was further compelled to put the Tower of London in his hands.