His father, Wilgils or Hilgis, an Angle or, as Alcuin styles him, a Saxon, of Northumbria, withdrew from the world and constructed for himself a little oratory dedicated to Saint Andrew. The king and nobles of the district endowed him with estates until he was at last able to build a church, over which Alcuin afterwards ruled.
A disciple of St Wilfrid, he was sent to the Abbey of Ripon almost as soon as he was weaned. Later he joined the Benedictines. He spent the years between the ages of 20 and 32 in the Abbey of Rathmelsigi, which was a centre of European learning in the 7th century. During this time he studied under Saint Egbert, who sent him and twelve companions to Christianize the pagan North Germanic tribes of Frisia, at the request of Pepin, Christian king of the Franks and nominal suzerain over that region. At the request of Pepin he travelled twice, finally being consecrated Bishop of the Frisians in the Church of St Cecilia in Rome. It was 21 November 695 and he was given the name of Clement. He was also given the pallium by the pope. He returned to Frisia to preach and to build numerous churches, among them a monastery at Utrecht, where he established his cathedral and is counted the first Bishop of Utrecht. In 698 he established an abbey at a Roman villa of Echternach, in Luxembourg near Trier, which was presented to him by Irmina, daughter of Dagobert II, king of the Franks.
Willibrord tried this while on a Carolingian-sponsored mission into Frisia with the express purpose of trying to convert the pagan Frisians living there in the hope that, once they had converted to Christianity, the Franks could gain control of the important trade port Dorestad, which they had up to that point been unable to do.
In 716 the pagan Radbod, king of the Frisians, retook possession of Frisia, burning churches and killing many missionaries.
After the death of Radbod in 719, Willibrord returned to resume his work, aided by Boniface, and under the protection of Charles Martel. His frequent visits to the Abbey of Echternach resulted in his being interred there after his death, and he was quickly judged to be a saint. In the Roman Catholic Church his feast is celebrated on 7 November outside England, but on 29 November in England, by order of Pope Leo XIII. In the Church of England, he is celebrated on 7 November.
Numerous miracles and relics have been attributed to him. On one occasion, the transport of his relics was celebrated thus "the five bishops in full pontificals assisted; engaged in the dance were 2 Swiss guards, 16 standard-bearers, 3045 singers, 136 priests, 426 musicians, 15,085 dancers, and 2032 players".
A Life was written by Alcuin and dedicated to the Abbot of Echternach. Alcuin probably made use of an older one written by a British monk, which is now lost. Bede also makes mention of Willibrord.
Nothing written by Willibrord can be found save a marginal note in the Calendar of Echternach giving some chronological data. A copy of the Gospels (Bibliothèque National, Paris, 9389) under the name of Willibrord is an Irish codex no doubt brought by Willibrord from Ireland.
In 752/753 Boniface wrote a letter to Pope Stephen II, in which is said Willibrord destroyed the Frisian pagan sanctuaries and temples. In the Life written by Alcuin are two texts about Willibrord and pagan places of worship. In one he arrived with his companions in Walcheren in the Netherlands where he smashed an idol of the ancient superstition. In the second text passage Willibord arrived on an island called Fositesland (possibly Heligoland) where a pagan god named Fosite was worshipped. Here he despoiled this god of its sanctity by using the god's sacred well for baptisms and the sacred cattle for food.