Resource: Professional Societies
- Lady Filmmakers Foundation
- Lambda Literary
- Las Fotos Project
- Las Maestras Center
- Latinas in STEM
- Le Lab Femmes de Cinema
- Legal Planet
- Lesbians Who Tech
- Letras Latinas
- LGBTQ Tech
- LGBTQ+ STEM
- Lighthouse Foundation
- Lionfish Universe
- Living Oceans
- Living Oceans
- Loggerhead Marinelife Center
- Lonely Whale Foundation
- Louisiana Bucket Brigade
- Louisiana Department of Environmental Quality
- Lucie Foundation
- Maine Aquaculture Association
- Maine Department of Environmental Protection
- Marine Activities, Resources & Education
- Marine Advanced Technology Education
- Marine Biological Association of the United Kingdom
- Marine Connection
- Marine Conservation Institute
- Marine Conservation Research International
- Marine Conservation Society
- Marine Environmental Observation, Prediction and Response Network
- Marine Fish Conservation Network
- Marine Mammal Center
- Marine Mammal Commission
- Marine Mammal Observer Association
- Marine Mammal Research Program
- Marine Mammals of Maine
- Marine Protected Areas
- Marine Society
- Marine Technology Society
- Marine Technology Society
- MarineCadastre.gov
- Maritime Archaeological and Historical Society
- Maritime Archaeological Association of NZ
- Marmara Islands Underwater Archaeological Research
- Maryland Department of the Environment
- Massachusetts Department of Environmental Protection
- Max Planck Institute for Marine Microbiology
- Medical Artists' Education Trust
- Medical Artists’ Association of Great Britain
- Mentoring Physical Oceanography Women to Increase Retention