He replaces John Shield, who left the government department to take the role of director of comms at the BBC in September last year, and is expected to take up the role on 3 March.
Robert Devereux, permanent secretary at the DWP, said: "[Richard] is a proven leader with experience in a range of senior posts. He will take charge of an excellent communications team at a vital time to ensure we continue to explain clearly the changes we're making to the welfare system for our claimants, our staff, our partners and the taxpayer."
Alex Aiken, executive director of government communications, said: "Richard Caseby is a first class communicator and manager who will make an excellent leader of the DWP communications team. They are already one of the best teams in government and I believe that Richard will build on their reputation and ensure that great communications supports the work of the department."
Caseby left his role at News UK as publisher of The Sunday Times and The Sun in June last year after more than two decades working at the company.