Sir David Walker, a former deputy governor of the Bank of England, will join as non-executive director from September 1 before succeeding Marcus Agius as chairman from November (Stuttgart: A0Z24E - news) 1.
His recruitment is designed to steer Barclays through the most tumultuous period in its history, following its £290m fine for manipulating the interbank lending rate Libor.
The scandal cost Marcus Agius, the current chairman, Bob Diamond, chief executive, and other executives their jobs.
Sir David is expected to join Barclays within weeks and replace Mr Agius as chairman in the autumn.
His appointment is likely to please shareholders keen for an established City name to help restore stability to Barclays.
Sir David's first role will be to recruit a successor to Mr Diamond. He will also need to examine the structure of Barclays as a universal bank housing both high street and investment banking operations.
Sir David drew up new guidelines for bank boards in the wake of the 2008 financial crisis, and his appointment is likely to be welcomed by the Bank of England and the Financial Services Authority, which helped to engineer Mr Diamond's departure.
Sir David said: "The UK needs a strong financial services sector and Barclays has a crucial role to play in ensuring that this country has a successful, well-governed banking industry."
Sir David, 72, who will receive £750,000 a year for the role, said his "immediate priority" was finding a new chief executive.