Robbert Gradstein is a Dutch botanist who works as an honorary researcher at the University of Göttingen, Germany, and the Museum National d'Histoire Naturelle of Paris. He has been a Professor of Botany and Director of the Botanical Garden of Göttingen University until his retirement in 2009. His research interests include the systematics and biogeography of tropical plants, especially bryophytes. He has done research in many parts of tropical America and in Asia, has directed numerous PhD theses and has published about 500 scientific papers and twenty books.