John Henry Warcup (29 October 1921 – 15 May 1998) was a New Zealand-born mycologist. He moved to the United Kingdom to undertake his PhD, examining distribution of fungi through soil profiles at Lakenheath Warren, in the University of Cambridge's botany department. He worked as a member of the Botany Department in the British Forestry Commission until 1951, when he accepted a position as a senior microbiologist in the Department of Plant Pathology at the then Waite Agricultural Research Institute, University of Adelaide where he worked until his retirement in 1986. In 1996 he was honoured by the British Mycological Society, becoming a Centenary Fellow. Warcup published over 70 papers in international peer-reviewed journals and was best known for his work with orchid mycorrhizal fungi, alon