Abigail Dillen is an environmental lawyer and executive at the environmental justice organization Earthjustice. Her work has been called "precedent setting" by multiple climate organizations. This includes, for example, defending the roadless rule, an environmental conservation policy that placed significant restrictions on timber removal and road construction or reconstruction in Inventoried roadless areas. She was profiled as a 2020 changemaker by Marie Claire.

Dillen directs Earthjustice's work to lead the country's transition away from fossil fuels toward cleaner sources, to improve energy efficiency, and to equip our nation's electrical grid to deliver clean, safe renewable energy. Since joining Earthjustice in 2000, Dillen has been the force behind numerous precedent-setting legal victories that have held polluters accountable and cleared the way for clean energy nationally.

Abigail has litigated precedent-setting cases that have held polluters accountable and cleared the way for clean energy nationally. These wins include: requiring the U.S. Environmental Protection Agency to promulgate first-ever standards to govern disposal of coal ash and limit the wastewater discharge of toxic pollutants from coal-fired power plants; blocking a $2 billion transmission project to transport dirty coal energy from the Ohio Valley to East Coast cities; blocking permits for new coal-fired power plants; and cutting off federal funding of new coal plants.