Meinhard Michael Moser (13 March 1924 – 30 September 2002) was an Austrian mycologist. His work principally concerned the taxonomy, chemistry, and toxicity of the gilled mushrooms (Agaricales), especially those of the genus Cortinarius, and the ecology of ectomycorrhizal relationships. His contributions to the Kleine Kryptogamenflora von Mitteleuropa series of mycological guidebooks were well regarded and widely used. In particular, his 1953 Blätter- und Bauchpilze (Agaricales und Gastromycetes) [The Gilled and Gasteroid Fungi (Agaricales and Gastromycetes)], which became known as simply “Moser”, saw several editions in both the original German and in translation. Other important works included a 1960 monograph on the genus Phlegmacium (now considered part of Cortinarius) and a 1975 study of members of Cortinarius, Dermocybe, and Stephanopus in South America, co-authored with the mycologist Egon Horak.
After showing interest in natural sciences in his youth, Moser studied at the University of Innsbruck. His university career began during World War II however, and was soon interrupted by military service. Stationed as a translator in eastern Europe, he was captured and placed in a prisoner-of-war camp. He was released in 1948, subsequently returning to Innsbruck to complete his studies. After completing his doctorate in 1950, Moser worked in England for six months, researching the symbiotic relationships between plants and fungi. Upon his return to Austria, he joined the Federal Forestry Research Institute, where he remained until 1968, conducting influential research on the use of mycorrhizal fungi in reforestation. He began lecturing at the University of Innsbruck in 1956, and in 1972 became the inaugural head of the first Institute of Microbiology in Austria. He remained with the Institute until his retirement in 1991, and his scientific studies continued until his death in 2002. An influential mycologist who described around 500 new taxa, Moser received awards throughout his life, and numerous fungal taxa have been named in his honour.