The Earth Island Institute was founded in 1982 by environmentalist David Brower.It organizes and encourages activism around environmental issues and provides public education. Funding comes from individual members and supporting organizations.

Through fiscal sponsorship, it provides the administrative and organizational framework for many individual projects that would otherwise be duplicating administrative requirements. Some of the projects have enjoyed significant success: a consumer-led boycott resulted in 100% of American tuna becoming "dolphin safe".