The 49-year-old left the BOA last December after being effectively demoted by chairman Colin Moynihan, who wanted to replace him with a more commercial background.

There was widespread sympathy for Clegg, the original architect of London's bid to host the 2012 Olympics and a highly-regarded Chef de Mission who at the Games in Beijing last year oversaw the most successful performance by a British team for a century.

Clegg starts his new role immediately and replaces Derek Bowden, the chief executive appointed five years ago by David Sheepshanks, one of the most powerful brokers in English football, who left the club as chairman earlier this month having stepped down as executive chairman in 2008 after 13 years in the position.

Marcus Evans, the owner of Ipswich Town, said: "Simon has built up an extensive knowledge of the sporting world through his role with the British Olympic Association and I'm delighted that he has agreed to join the football club.

"Not only does he have a wealth of experience in the world of sport, but he has proved to be a highly successful businessman and team leader and will have a key role in moving Ipswich Town forward."

Clegg said: "I am hugely flattered and excited about taking on this role at such a prestigious football club.

"Marcus Evans and I are absolutely aligned about our aspirations for the club both on and off the pitch.

"I have joined Ipswich Town because I am absolutely convinced that working together with the fans, sponsors, community and staff we can once again put the Club back in its rightful place in the Premier League."

Ipswich were formerly one of Europe's leading clubs, winning the FA Cup in 1977 and the UEFA Cup in 1981, but were relegated from the Premiership in 2002.

They were taken over in December 2007 for £44 million by businessman Evans.

The figure included covering Ipswich's £32 million debt.

In 1988, at the age of 28, Clegg was promoted as one of the youngest majors in the British Army, having joined as a private soldier, before leaving to follow a career in sports leadership and administration a year later as the deputy general secretary of the BOA.

His final tour of duty was with the 7th Parachute Regiment, Royal Horse Artillery.

Clegg, a former manager of Britain's biathlon team, became the BOA's first chief executive in 1997.

He had been involved in 12 Olympic Games, both Summer and Winter, the last six as Chef de Mission, including Beijing.

He was awarded the OBE in 2001 for management of Britain's at the Sydney Olympics, at the time Britain's most successful performance for 80 years, and four years later was made a CBE for his contribution to London's successful bid to host the 2012 Olympics.

On returning from Singapore, where he was one of three British signatories on the 2012 Host City contract, he led a meeting of Olympic national governing bodies and national agencies to set a target of aspiring to finish fourth in the 2012 medal table - a target they achieved ahead of schedule in Beijing.