Mr Fison was CEO of Skanska UK from 2002 until July 2008 and previously held senior management positions at Balfour Beatty.
He joins at a crucial stage in the project as the pace of construction picks up considerably during 2009 with key venues and infrastructure beginning to emerge from the ground.
Ms Jowell has also reappointed the current board members who were originally appointed in 2006, apart from Sir Peter Mason, who has stepped down from the Board to concentrate on his other business interests.
Mr Fison and the current Board Members have been appointed until 30 September 2012.
The Board Members are:
* Lorraine Baldry, former chair of the London Thames Gateway Development Corporation
* Tony Ball, former chief executive and managing director of British Sky Broadcasting
* Barry Camfield, former assistant general secretary of the Transport and General Workers Union
* Neale Coleman, Mayor of London's Olympic adviser
* Stephen Duckworth, chief executive of Disability Matters
* Christopher Garnett, deputy chair, Transport for London
* Sir Roy McNulty, chairman of the Civil Aviation Authority
* Baroness Morgan of Huyton, former policy adviser at no 10 Downing Street
* Kumar Muthalagappan, managing director of the Pearl Hotels and Restaurants Group
* Sir Nicholas Serota, director, Tate
* David Taylor, chairman of Silvertown Quays