Environmental Defense (formerly known as the Environmental Defense Fund or EDF), is a US-based nonprofit environmental advocacy group. The group is known for its work on issues including global warming, pollution prevention, and market-based solutions to environmental problems.

Environmental Defense is perhaps best known for its role in working with McDonald's to phase out use of styrofoam hamburger containers; this was criticized by other groups on the grounds that a full audit had suggested cardboard containers used more energy to produce. In addition, the group was involved in the 1990 amendments to the Clean Air Act, which enacted emissions trading mechanisms to reduce acid rain that results from sulfur dioxide pollution.