André Aptroot is a Dutch mycologist and lichenologist.
In 1993 he did his PhD at the University of Utrecht under the supervision of Robbert Gradstein. His dissertation was titled "Systematic studies on pyrenocarpous lichens and related fungi".
He specializes in fungi and lichens on which he has several publications to his name. He has worked as curator at Centraalbureau voor Schimmelcultures.
He is the founder of the Consultancy for Bryology and Lichenology which is located in Soest where there is a herbarium with a collection of lichens mainly from the Netherlands and the tropics. From 2008 he has been collection manager at Pinetum Blijdenstein in Hilversum. He is a member of the International Association for Lichenology and the American Bryological and Lichenological Society.
He is a visiting professor at the Federal University of Mato Grosso do Sul in Campo Grande, Brazil. Because of Aptroot's broad expertise in tropical lichens, his colleague Ingvar Kärnefelt has called him "a Müller Argoviensis of our time". Aptroot is the author or co-author of three of the thirty most highly cited publications published in the scientific journal The Lichenologist from 2000 to 2019.