Thomas of Bayeux (died 18 November 1100) is Archbishop of York from 1070 until 1100.

He is educated at Liège and becomes a royal chaplain to Duke William of Normandy, who later becomes King William I of England.

After the Norman Conquest, the king nominates Thomas to succeed Ealdred as Archbishop of York.

After Thomas' election, Lanfranc, Archbishop of Canterbury, demands an oath from Thomas to obey him and any future Archbishops of Canterbury; this is part of Lanfranc's claim that Canterbury is the primary bishopric, and its holder the head of the English Church.

Thomas counters that York had never made such an oath.

As a result, Lanfranc refuses to consecrate him.

The King eventually persuades Thomas to submit, but Thomas and Lanfranc continue to clash over ecclesiastical issues, including the primacy of Canterbury, which dioceses belonged to the province of York, and the question of how York's obedience to Canterbury will be expressed.

After King William I's death, Thomas serves his successor, William II, and helps to put down a rebellion led by Thomas' old mentor Odo of Bayeux.

Thomas also attends the trial for rebellion of the Bishop of Durham, William de St-Calais, Thomas' sole suffragan, or bishop subordinate to York.

During William II's reign, Thomas once more becomes involved in the dispute with Canterbury over the primacy when he refuses to consecrate the new Archbishop of Canterbury, Anselm, if Anselm was named the Primate of England in the consecration service.

After William II's sudden death in 1100, Thomas arrives too late to crown King Henry I, and dies soon after the coronation.