Ronald Gerhardus Wilhelmus Cornelissen (born 12 December 1964) is a Dutch Roman Catholic clergyman. Since 11 October 2025, he has served as the 4th bishop of the Diocese of GroningenâÂÂLeeuwarden. His motto is Perigrinantes in spem (Pilgrims of hope).
Cornelissen was born in Gaanderen as the youngest of four children. He attended the Saint Augustine School in Gaanderen and later the Isala College in Silvolde, where he completed HAVO and VWO education. He studied theology at the Ariëns Institute in Utrecht.
On 19 October 1996, he was ordained a priest in St. CatherineâÂÂs Cathedral in Utrecht by Cardinal Simonis. He subsequently served in pastoral assignments in Slagharen, Denekamp, Deventer, Raalte, and Rijssen. In addition, he was involved in the organization and spiritual guidance of pilgrimages. From 2009 until 2025, he served as episcopal vicar of the Deventer vicariate.
On 7 July 2025, Cornelissen was appointed bishop of the Diocese of GroningenâÂÂLeeuwarden. He succeeded Ron van den Hout, who was appointed bishop of the Diocese of Roermond. On 11 October 2025, Cornelissen received episcopal consecration and took possession of the episcopal see at St. JosephâÂÂs Cathedral in Groningen. The Archbishop of Utrecht, Cardinal Eijk, served as the principal consecrator.