Paul Deighton will be the new chief executive of the London Organising Committee for the 2012 Olympic Games.
Deighton is currently the chief operating officer of Goldman Sachs European Business and has been with the company since 1983.
The 49-year-old will have day-to-day control of the build-up to London hosting the Games.
"As a Londoner passionate about sport, I am extremely excited about this opportunity," he said.
"This is the only job I would have considered leaving Goldman Sachs for.
"The Games has an enormous potential to inspire young people. The memories of the Games I listened to and watched in my childhood are some of the most inspirational memories I have.
"To help stage the Olympic Games and Paralympic Games, the world's most important sporting and cultural events, in my home city is a dream come true.
"The London 2012 Games represents an unprecedented and unrepeatable opportunity to combine so many of my professional experiences with my love for sport.
"Few projects or events have the scope or the impact on a city or its communities and citizens like the Olympic Games. I am delighted to be part of it."
Deighton will handle the day-to-day running of the London 2012 Olympic Games Organising Committee (LOCOG) and will oversee programmes such as sponsorship, marketing, ticketing and the torch relay.
He will work closely with London 2012 chairman Lord Coe.
The appointment ends a three-month search with more than 1,000 people expressing an interest and 300 going on to apply.
"We selected Paul because of his experience in leading large international organisations and projects as well as his track record of managing and growing large teams of people in complex and diverse environments," said London 2012 chairman Lord Coe.
"He is the right person to lead the LOCOG on its mission to produce an outstanding Olympic Games for the athletes and youth of the world in 2012."
Deighton's appointment follows that of chief executive David Higgins and chairman Jack Lemley to the London Olympic Delivery Authority.
Meanwhile, Graham Newsome is in line to become director of communications at the British Olympic Association (BOA).
Newsome, a press aide to Gordon Brown, was BOA chairman Colin Moynihan's media chief while he was minister for sport.