- Macquarie University [Sydney]
- Marine Biology Research Division [La Jolla, California]
- Marine Microbiology Research Group (MMRG)
- Marine Physical Laboratory
- Matière et Systèmes Complexes
- Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
- Max Planck Institute for Marine Microbiology
- Max-Planck-Gesellschaft
- Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research
- Medical College of Virginia
- Mer et santé
- Meteorological Research Institute [Tsukuba]
- Meteorological Service of Canada
- Microbial Ecology, Center for Ecological and Evolutionary Studies
- Microbiology
- Middle East Technical University [Ankara]
- Mines Nantes
- Ministry of Land and Resources
- Ministère de la défense (1936-....)
- MoNOS, Huygens Laboratory
- Modèles en biologie cellulaire et évolutive
- Monash University [Clayton]
- Monterey Bay Aquarium Research Institute
- Muséum national d'Histoire naturelle
- Myongji University
- Météo-France