Anna Dixon, chief executive of the Centre for Ageing Better, is to step down in June.
Dixon has led the charitable foundation, which aims to help people enjoy later life, since 2015.
She was previously director of strategy and quality at the Department of Health and a visiting fellow at The London School of Economics.
Dixon said it was the right time for her to step down after five-and-a-half years in the role.
The centre declined to give any further information on why Dixon was leaving, or her plans.
“We wish Anna every success in her future career and are deeply indebted to her for the outstanding work she has done for the centre,” the charity said.
Dixon said: “It has been a pleasure and a privilege to work with colleagues at Ageing Better and across a broad range of sectors to make a real difference to people entering later life.
“I have enjoyed advocating at the highest levels, and overseeing the development and delivery of a wide range of programmes to support older workers, to help improve our poor housing stock, give a boost to physical activity in later life, and strengthen communities and volunteering.
“It is always a hard decision to leave any organisation, but I feel that the time is right as Ageing Better enters its next phase of work.”
Dixon was awarded an MBE in the most recent New Year Honours for services to wellbeing in later life.
She published a book last year, called The Age of Ageing Better? A Manifesto For Our Future, aimed at helping policy-makers and practitioners ensure no one misses out on a good later life.