The coat of arms of the Order of St. Willibrord is derived from what was the Prince-Bishopric of Utrecht. The Bishopric of Utrecht was originally founded in A.D. 695 by St. Willibrord, a missionary Benedictine monk from then the Kingdom of Northumbria in England, who was consecrated a bishop by Pope Sergius I, with permission from Prince Pepin II of Herstal, then Ruler of the Franks, who admired the great zeal with which Willibrord preached the Gospel and converted the pagans in what is now the Netherlands. Bishop and Confessor, St. Willibrord is known as "Apostle to the Frisians," first Bishop of Utrecht and Patron of our Order. In 1024, the Bishops of Utrecht were made Princes of the Holy Roman Empire.

The prominent Chi Rho cross derived from the first letters of Christ in Greek, an ancient symbol of Christianity, which first appeared to the Roman Emperor Constantine, the Great as a vision, which he believed inspired his military success at the Battle at the Milvian Bridge in Rome, and moved him in conversion to Christianity.