Earth First! (EF!) is a network of environmental activists, living mostly in the United States, committed to preserving wilderness and biological abundance.

It was founded in 1980 by Dave Foreman, Mike Roselle, and a number of other environmentalists who were disillusioned with so-called mainstream environmentalism. Foreman and the others previously worked with Washington, D.C.–based environmental groups. According to EF! founders, however, these organizations were always willing to compromise their ultimate goals to be active players in the policy process. The founders of EF! sought to provide principles and a loose organizational structure for people who were no longer willing to compromise in their efforts to protect nature. The group's motto is "No Compromise in the Defense of Mother Earth!"

EF! is unique within the environmental movement for its philosophical orientation, political strategies, and...