Friends of the Earth has announced that Craig Bennett, its director of policy and campaigns, will take over as chief executive in the summer.
He will replace Andy Atkins, who announced earlier this year that he would stand down after seven years in the role.
Bennett, who is currently on sabbatical undertaking a policy fellowship at the Centre for Science and Policy at the University of Cambridge, has been director of policy and campaigns at the environmental campaigning charity since 2010.
Before that he was deputy director at the University of Cambridge Institute for Sustainability Leadership and co-director of the Prince of Wales's Corporate Leaders Group on Climate Change.
Roger Clarke, chair of Friends of the Earth, said: "Craig has shown himself to be a visionary and inspirational leader, and his commitment to Friends of the Earth and our objectives runs through him like a stick of rock.
"From dangerous climate change to the decline in nature, we have no doubt that he will help Friends of the Earth to raise its game to meet the major environmental challenges we face."
Bennett, who will take up the new role on 1 July, said he first started campaigning with Friends of the Earth as a teenager and that it was an incredible honour to be offered the new role.
"For more than 40 years, Friends of the Earth has been the one place where people can take practical and political action locally and as part of the world’s largest grass-roots environmental network," he said.
Bennett's salary will be between £80,000 and £90,000, the same as the outgoing chief.