William Bardolf (died before 5 January 1276) was an English landowner, courtier, soldier and royal official.
After being in attendance on King Henry III when visiting France in 1230, he led the military expedition to the island of Lundy in 1242 which captured the pirate William de Marisco and his fellow outlaws.
He was in the King's service in 1242 during campaigns in Wales and Scotland and in 1255 accompanied Eleanor, the queen consort, to France.
These decades of service to the Crown brought him rewards in money and prestige, such as grants of free warren and the right to hold fairs and markets in his manors, together with favourable terms for settlement of debts to the king.
[1] In the political crisis of 1258, however, he switched to the baronial opposition, being chosen at the parliament of Oxford as one of the twelve baronial members of the council of twenty-four appointed to reform the realm, and under the Provisions of Oxford was made Constable of Nottingham Castle,[1][2] In 1259 he was elected to the parliamentary committee of twelve and in 1261 was using his local influence in Norfolk to obstruct the work of the king's sheriff.