Barclays has confirmed Jes Staley as its new group chief executive officer, taking the role from December 1.
He will also join the Barclays board as a director.
Mr Staley worked at JP Morgan for more than three decades before quitting in 2012 to join the hedge fund BlueMountain Capital Management.
Speaking about his widely expected appointment, Mr Staley said he would continue building trust in the organisation and focus on boosting shareholder returns.
"Barclays is a very valuable franchise, from its retail and commercial banking presence in the UK, its strength in cards and payments, its strong position in Africa, to its Investment Bank," he said.
"Maximising the potential of this franchise means building on our competitive advantages and developing new ones in order to generate strong returns on capital. If we do this, increased value for our shareholders will follow at the same time as Barclays' long history of leadership is continued and enhanced."
It brings to an end a three-month search to replace previous boss Antony Jenkins, who was sacked in July for lacklustre revenue growth and a flat share performance.
Mr Staley's appointment is a sign that Barclays wants to renew its focus on investment banking after Mr Jenkins - a retail banker - had toned down this side of the business in the aftermath of the Libor rate-fixing scandal.
Barclays chairman John McFarlane said Mr Staley "understands corporate and investment banking well, the re-positioning of which is one of our major priorities. After an extended process, I now know Jes well, and we are in agreement on the way forward.
"He is a man of enormous integrity, and someone who both understands the business, but also the importance of cultural reform and the need to conduct our business in a way that we can all be proud of. I look forward to working with him in what will be an exciting and important period for our company as we seek to accelerate the delivery of improved shareholder returns."