William of Wallingford was, from youth up, a monk of St. Albans, no doubt having been sent there through the influence of the Prior of his home town. He only left the house to study at university, probably at Oxford. He was an administrator rather than a recluse and, at the time of the death of Abbot John Stoke on 14th December 1451, was already archdeacon, cellarer, bursar, forester and sub-cellarer of the Abbey of St. Albans. He was a candidate for the succession when John Wheathampstead was unanimously elected on 16th January 1452. Throughout the abbacy of Wheathampstead, Wallingford held office as 'official general,' archdeacon and also as chamberlain. Faction raged high among the monks and grave charges were then, or later, brought against Wallingford, which are detailed at great length in Wheathampstead's 'Register'. They are, however, evidently an interpolation, probably by a monk jealous of Wallingford, and Wheathampstead not only took no notice of these accusations, but retained Wallingford in all his offices. In 1464, he was, as archdeacon, appointed by the abbot as a member of a commission for the examination of heretics. Ramridge, Wallingford's successor as abbot, says that he first became distinguished as archdeacon for his care of education, training ten young monks at his own expense, and for the lavish attention he bestowed upon the abbey buildings and treasures. He built "many fair new buildings" for the abbey, ranging from the library to a stone bakehouse, while those buildings which were falling into a ruinous state he repaired. He also presented the abbey with many rich treasures, such as a gold chalice and precious gold-embroidered vestments. Their value was 980 marks (£653-6s-8d).

When, upon the death of Wheathampstead on 20th January 1465, William Albon, the prior, was, on 25th February, elected his successor, Wallingford took a leading part in the election. On 18th March, the new abbot, with the common consent of the monks, created Wallingford prior of the monastery. His previous office of archdeacon, he also continued to exercise. In 1473, he was granted, with others, a commission for the visitation of the curates and vicars of St. Peter's, St. Andrew's, St. Stephen's and St. Michael's of the town of St. Albans. As prior, he kept up his interest in the maintenance of the monastic buildings, spending £360 on the kitchen and, within eight years, laying out a thousand marks (£666-13s-4d)  on the repairs of farms and houses. He built a prior's hall and added all that was necessary for it.

After Abbot Albon's death on 1st July 1476, Wallingford was, on 5th August, unanimously elected to succeed him. Wallingford's register covers the years from 1476 to August 1488, though certain leaves are torn out from the end of it. Wallingford took little part in external affairs. He resisted, successfully, certain claims of Archbishop Bourchier over the abbey, which were decided in the abbot's favour upon appeal to Rome. In 1480 Wallingford was appointed, by the general chapter of Benedictines at Northampton, visitor of all Benedictine monasteries in the diocese of Lincoln, but he commissioned William Hardwyk and John Maynard to conduct the visitation in his place. His government of the abbey was marked by regard for strict discipline tempered with generosity. Thus, while he deposed John Langton, Prior of Tynemouth, for disobedience to his 'visitors', he gave letters testimonial for the absolution of a priest who, by misadventure, had committed homicide. He also freed certain villeins and their children. In 1487, Wallingford sent John Rothebury, his archdeacon, to Rome in order to try to win certain concessions for the abbey, but the mission proved a failure.

Wallingford's abbacy shows some of the weak points characteristic of fifteenth century monasticism. There is a desire to make the best of both worlds. The lay offices of the abbey were turned to advantage. For example, in 1479, Wallingford conferred the office of seneschal or steward of the liberty of St. Albans, with all its emoluments, on William, Lord Hastings, notwithstanding the fact that Abbot Albon had already, in 1474, conferred the same on John Forster for life. Three years afterwards, Wallingford gave the office jointly to the same Lord Hastings and John Forster. However, Lord Hastings was put to death by King Richard III soon afterwards and Forster, after being imprisoned in the Tower for nearly nine months, "in hope of a mitigation of his punishment, did remit and release all his title and supreme interest that he had in his office of seneschal of St. Albans". This is one instance of several which show that the lay offices of the abbey were used for selfish ends. The attitude of Wallingford to the bishops was conciliatory as a rule, sometimes even obsequious. Thus, when he feared the loss of the priory at Pembroke, given by Duke Humphrey, through Edward IV's resumption of grants made by his three Lancastrian predecessors, he applied humbly to the chancellor, George Neville, Bishop of Exeter, for his good offices and, through him, secured a re-grant. The bishop, in return, was later granted the next presentation of the rectory of Stanmore Magna in Middlesex. Some historians have, however, been unduly severe in their interpretation of many of Wallingford's acts. From the golden opinions of his immediate successor in the abbacy, Thomas Ramridge, no less than from the simple entries in Wallingford's own register, it is clear that he was efficient and thorough-going, an excellent administrator and a diligent defender of his abbey. He voluntarily paid £1,830 of debts left by his predecessor. He built a noble altar-screen, long considered the finest piece of architecture in the abbey. Upon this, he spent eleven hundred marks (£733-6s-8d), and another thousand marks (£666-13s-4d)  in finishing the chapter-house. He also built, at a cost of £100, a small chantry near the altar oh the south side, in which he built his tomb, with his effigy in marble. His tomb bears the inscription:

Gulielmus quartus, opus hoc laudabile cuius Extitit, hic pausat: Christus sibi praemia reddat.

Two fine windows, a precious mitre and two rich pastoral staves were other gifts the abbey owed to his munificence. When he died in late May or very early June 1492, leaving the abbey entirely freed from debt.

The main interest of Wallingford's abbacy lies in the fact that the art of printing which, having been brought into England a few years before by Caxton, was then introduced into the town of St. Albans. The whole subject of the relation of the St. Albans press to other presses is obscure, and even the name of the St. Albans printer and his connection with the abbot unknown. All that is certain is that, between 1480 and 1486, this unknown printer issued eight works, the first six in Latin, the last two in English. The most important and last of these was the famous 'Boke of St. Albans'. All that is clearly known of the St. Albans printer is that in Wynkyn de Worde's reprint of 'St. Albans Chronicle' the colophon states: "Here endeth this present chronicle, compiled in a book and also imprinted by our sometime schoolmaster of St. Alban". There is no clear proof of any closer relation between Wallingford and the "schoolmaster of St. Alban"  than between John Esteney, Abbot of Westminster, and William Caxton, who worked under the shadow of Westminster Abbey. Yet the probabilities of a close connection, in a little place like St. Albans, between the abbot, who was keenly interested in education, and the 'schoolmaster', who was furthering education by the printing of books, are in themselves great, and are confirmed by the fact that two of the eight books printed between 1480 and 1480 bear the arms of the Abbey of St. Albans.