This is a list of notable events relating to the environment in 2015. They relate to environmental law, conservation, environmentalism and environmental issues.

• The eight Millennium Development Goals, agreed to in 2001 by all 193 United Nations member states and at least 23 international organizations, are set to be achieved.^{[needs update]}

May

• 24 May: publication of Pope Francis' encyclical letter, Laudato si', subtitled On Care for Our Common Home.^[1]

• Human impact on the environment
• List of environmental issues