- ATTRA– Sustainable Farming Internships and Apprenticeships
- Idealist– a good place to begin your search for sustainability jobs, internships and volunteer opportunities
- Chesapeake Bay Foundation
- Chesapeake Bay Trust
- Chesapeake Climate Action Network is the first grassroots, nonprofit organization dedicated exclusively to fighting global warming in Maryland, Virginia, and Washington, D.C.
- Energy Action Coalition is a coalition of 50 organizations addressing climate change by winning clean energy victories at the local, state, national, and international level
- Environmental Defense Fund combines science, economics, and law to find economically sustainable solutions to environmental problems
- Federal Environmental Protection Agency
- Fish and Wildlife Service
- Green America (formerly Co-op America) strives to harness economic power—the strength of consumers, investors, businesses, and the marketplace—to create a socially just and environmentally sustainable society
- League of Conservation Voters is a bipartisan group working to educate voters and win elections on behalf of the environment
- Maryland Department of Agriculture
- Maryland Department of the Environment
- Maryland Department of Natural Resources
- Maryland Department of Transportation
- National Audubon Society works through advocacy, policy, science, litigation, sanctuary management, grassroots outreach and education to protect birds and their habitats
- National Oceanic and Atmospheric Administration
- National Wildlife Federation unites individuals, organizations, businesses and government to protect nature and wildlife
- Natural Resource Defense Council protects the environment and human health through advocacy, litigation, research and education
- The Nature Conservancy preserves habitats and species by buying the lands and waters they need to survive
- Patuxent Riverkeeper is a nonprofit watershed advocacy organization affiliated with the Waterkeeper Alliance
- Rainforest Action Network protects rainforests through education, grassroots organizing and non-violent direct action
- Sierra Club promotes environmental conservation by influencing public policy
- Sierra Student Coalition works to train, empower, and organize youth to run effective campaigns that result in tangible environmental victories and that develop leaders for the environmental movement
- St. Mary’s County Department of Land Use and Growth Management
- The Wilderness Society protects wild places in the United States through public education, policy work and litigation
- World Wide Opportunities on Organic Farms
- World Wildlife Fund is dedicated to building a future where people live in harmony with nature