Ministers had given the Games a total budget of £9.29 billion, but the projected cost is £8.92 billion.
Sports Minister Hugh Robertson said construction and transport for the Games had cost less than expected, and that the underspend was a “conservative” estimate as some contingency funding is yet to be released.
He described organisers’ delivery of the events on budget as “a tremendous success”.
“I have no doubt that London 2012 has set a new benchmark for the management of Olympic and Paralympic Games in future,” he said.
“The predictions that I made this summer that we could bring this project in at under £9 billion has almost certainly been met.”
Organisers are still in talks with the disgraced security firm G4S over how much it should repay following its failure to provide enough guards for the Games, which forced the government to draft in 4,700 troops to fill the gaps.
The company said in August that it expected to lose £50 million over the fiasco.
Around £103 million of Olympic contingency funding is still being held to cover ongoing projects such as the transformation of the Athletes’ Village into housing.
An additional £480 million of uncommitted contingency funding remains to be released, while around 2,000 contracts have yet to be closed.
The Olympic Delivery Authority’s construction and transport programme cost an estimated £6.71 billion, £47 million less than the previous estimate.