Carolus Adrianus Johannes "Karel" Kreutz (born 1954) is a Dutch orchidologist, botanical writer and taxonomist, currently affiliated with the Centre for Biodiversity Naturalis in Leiden, Netherlands.

[1][2] He is regarded as an exceptionally experienced orchidologist,[3] and has published orchid floras of Cyprus, Turkey, Rhodes, Crimea, Netherlands, Belgium and Germany,[4] and is currently preparing a major overview in ten volumes of all orchid taxa in Europe, North Africa and the Middle East, employing modern taxonomy, nomenclature and research techniques.

[5] Kreutz has published over 200 scientific papers, and is the scientific authority for over four hundred plant taxa, predominantly in the Orchidaceae, but also in the genus Orobanche.

[6][7] The following orchid species have been named in recognition of Kreutz' work on the Orchidaceae: