Father Chrysanthus O.F.M. Cap. (1 September 1905 – 4 May 1972), born Wilhelmus Egbertus Antonius Janssen, was a Dutch priest and biology teacher. He was known for his studies in arachnology. Initially he was concerned with the spiders of the Netherlands but he became a specialist on New Guinea spiders. Two spider species were named in his honor following his death.