The Department for International Development (DfID) has poached Hardy to be its head of news.
He follows fellow BBC correspondent Guto Harri and former Sunday Times political editor David Cracknell into the world of PR.
At DfID, he will report to director of comms Paul Mylrea. He replaces Vickie Sheriff, who moved to the Ministry of Justice in January.
Mylrea said: 'James will work to improve the reputation of the DfID.'
Hardy joined the BBC in 2004. Before that he was Daily Mirror political editor and Sunday Telegraph home affairs editor.