The covering of the Stadium's cable-net roof creates the correct conditions on the field of play for athletes and provides protection for two-thirds of spectators.
A total of 45,000sq m of material in 112 panels, stretched between an outer truss and inner tension ring, has been fitted by a team of 23 expert abseilers.
ODA Chairman John Armitt said: 'The Olympic Stadium is the most visible symbol of the huge progress that has been made on the construction of the Olympic Park and the infrastructure which is transforming east London.'
The ODA also published its annual report and accounts, along with expenses for the Board and Directors for 2009-2010.
'The senior management team have ensured that this multi-million pound project with a fixed deadline is on track and within budget, making £700m savings to date,' said John Armitt.
'The ODA was created solely for a time-limited task and we will be scaling down from next summer. These are short-term jobs with no enhanced redundancy arrangements and all Directors will be voluntarily taking a pay freeze this year, as well as deferring a proportion of performance-related pay until after the Games.'