Rolande Anderson, head of the Office for Civil Society, will be replaced by Gareth Davies, the director of the Cabinet Office Strategy Unit, when her one-year term runs out next month.
Davies, who was previously a Downing Street senior policy adviser on pensions and welfare, started working at the OCS yesterday and will work alongside Anderson until she steps down in December.
The department said that Davies would work with the behavioural insights team, part of the Cabinet Office Strategy Unit, to develop new ways of encouraging volunteering and philanthropy.
In a statement, Davies said: "I am looking forward to taking responsibility for the government's ambitious agenda for opening up public services, encouraging social action and giving more power to local communities by bringing together the best of the Strategy Unit and the Office for Civil Society."
Anderson will leave the civil service when she steps down as head of the OCS.