Environmental defenders or environmental human rights defenders are individuals or collectives who protect the environment from harms resulting from resource extraction, hazardous waste disposal, infrastructure projects, land appropriation, or other dangers. In 2019, the UN Human Rights Council unanimously recognised their importance to environmental protection. The term environmental defender is broadly applied to a diverse range of environmental groups and leaders from different cultures that all employ different tactics and hold different agendas. Use of the term is contested, as it homogenizes such a wide range of groups and campaigns, many of whom do not self-identify with the term and may not have explicit aims to protect the environment (being motivated primarily by social justice concerns).
Environmental defenders involved in environmental conflicts face a wide range of threats from governments, local elites, and other powers that benefit from projects that defenders oppose. Global Witness reported 1,922 murders of environmental defenders in 57 countries between 2002 and 2019, with indigenous people accounting for approximately one third of this total. Documentation of this violence is incomplete. The UN Special Rapporteur on human rights reported that as many as one hundred environmental defenders are intimidated, arrested or otherwise harassed for every one that is killed.
There is a long history of people protecting their environment from the harms associated with economic production. This has previously been discussed in terms of environmental justice, environmentalism of the poor, ecological distribution conflicts, settler colonialism, and other theories that closely relate to the environmental defender framework. Academic papers, the media, and various NGOs have increasingly used the term environmental defender, environmental human rights defender, and land defender to describe people struggling to protect their land from pollution or dispossession, especially since the UN Declaration on Human Rights Defenders in 1998.