Nick Jones, currently interactive director for the Central Office of Information (COI), has been appointed interim head of digital for the Prime Minister's Office and Cabinet Office.
Jones will continue his work at the COI, while also overseeing digital communications at Number 10.
The move comes after the COI was earmarked for closure in June following a major shake-up of government communications. The COI has already seen its budget cut from £532m in 2009/10 to an estimated £168m in 2010/11.
Jones' appointment is temporary as the government is considering the scope of its digital services in the context of the communications reforms, said a Cabinet Office spokeswoman.
Rishi Saha left as Downing Street's head of digital communications in June to become regional director of Hill & Knowlton across Australia, the Middle East, and South and Central Asia.