Marc-André Selosse completed his university studies at the Ecole Normale Supérieure, Paris and he was awarded a PhD from the Université Paris Sud (Orsay) in 1998. He has held positions as a forest engineer, Associate Professor at University Paris VI, and Professor at the University of Montpellier. In 2012, he was appointed Professor at the Muséum national d'Histoire naturelle, Paris, which was founded as the Royal Botanical Gardens in 1653. The Museum is presently devoted to research and teaching of natural sciences.

Marc-André teaches microbial ecology, the biology of interactions (especially symbiosis), evolution and plant ecology. A major aspect of his teaching work involves training future high-school biology teachers, and he recently joined the committee establishing biology curricula for French high schools. He is committed to the popularization of science, and has published c. 100 outreach papers and a textbook on symbiosis.

His research focuses on mycorrhizal symbioses. More specifically, his team has an interest in fungal populations and communities, with a specific focus on the ecology of mycorrhizal networks. He also works on the physiology of mycoheterotrophic plants, especially orchids.