Walter de Cantilupe was Bishop of Worcester from 1236 until his death in 1266 and a prominent ecclesiastical supporter of baronial reform in mid-13th-century England. Closely aligned with Robert Grosseteste, he opposed the appointment of foreign clerics to English benefices and defended episcopal autonomy against royal interference.

Cantilupe was an active ally of Simon de Montfort during the baronial movement against Henry III. In 1258 he was elected as one of the twenty-four commissioners appointed under the Provisions of Oxford ⓘ to reform royal administration. During the Second Barons’ War ⓘ (1264–1267), he blessed de Montfort’s forces before the Battle of Lewes and hosted de Montfort on the eve of the Battle of Evesham, where the earl was killed. Cantilupe died on 4 February 1266.