Gerardus Gul (27 October 1847 – 9 February 1920) served as the seventeenth Archbishop of Utrecht from 1892 to 1920.
He is known for his role in assisting the persons who would later found the Polish National Catholic Church in the United States, as well as for consecrating Arnold Harris Mathew, the founder and first bishop of the Old Catholic Church in Great Britain.
On 21 November 1897, Gul assisted Eduard Herzog of the Swiss Christian Catholic Church and Theodor Weber of the Old Catholic Church of Germany with the consecration of Antonius Stanislas Kozłowski, who was elected by a number of Polish congregations in Chicago that were dissatisfied with the control exercised over their church properties by mostly-Irish Roman Catholic bishops.
On 29 September 1907, at Utrecht, Gul consecrated Franciszek Hodur, from Scranton, Pennsylvania, for the Polish National Catholic Church, assisted by Johannes Jacobus van Thiel, Bishop of Haarlem, and Nicholas B. P. Spit, Bishop of Deventer.
In 1908, the Union of Utrecht approved the establishment of a mission in Great Britain, and on 28 April 1908 Gul consecrated Arnold Harris Mathew at St. Gertrude's Cathedral in Utrecht for the purpose of establishing the Old Catholic Church in the United Kingdom.