He was a Benedictine monk at Holy Trinity Priory, Wallingford, Berkshire (now Oxfordshire), England and like John of Wallingford and Richard of Wallingford, moved from this cell of St Albans Abbey to the abbey itself. He was a favourite of John Stoke, 44th abbot of St Albans, also from Wallingford. On his deathbed in 1451, Stoke was supposed to have given William and Thomas Wallingford, his senior chaplain, charge over 1000 marks but after his death they could only account for 250 marks. The abbot John Wheathampstead who succeeded Stoke suspected the two over the money. Nevertheless, William of Wallingford was later appointed abbot in 1476, after the death of William Albone, apparently for his financial acumen, at a time when the abbey was in debt. William of Wallingford managed to get rid of the debt whilst also spending on the abbey. He built the high altar known as the Wallingford Screen at a cost of £733 and completed the chapter house. The statues on it were destroyed during the Dissolution but were replaced in Victorian times.