The former Homes and Communities Agency boss, who took the lead role at the Department for Communities and Local Government last year, will retain his role while also taking over from Gus O’Donnell as head of the civil service.
His combined extra responsibilities will see him split his time between Whitehall and Eland House. Sir Bob will be paid £200,000 for taking both roles.
Sir Bob said: “I am delighted and honoured to be given this leadership role at such an important time for the civil service.
“We have immense strengths in the service that we should be justly proud of, but we must also embrace change. I want to engage all parts of the civil service in the reform process.”