Matthew Frost, chief executive of the development charity Tearfund, is to stand down next year.
Frost announced this week that he would leave the Christian charity at the end of September 2015, by which time he will have completed 10 years in the role.
He said he had announced his departure so far in advance in order to allow a smooth transition to his successor.
A Tearfund spokeswoman said Frost would spend the next year considering what he would do when he leaves the charity.
"I love Tearfund," said Frost. "I’ll be sad to leave my current role, but my heart will very much remain with the millions of people around the world whom we serve and the many thousands of our passionate and dedicated supporters and staff. I will continue to support Tearfund wholeheartedly in any way I can."
Clive Mather, chair of Tearfund, said: "Matthew’s leadership has been central to setting our vision, shaping our culture and in everything we’ve achieved since 2005. We have so much to thank him for."