More than 50 million people in the UK watched TV coverage of London 2012 - equivalent to 90% of the population.
New figures show that 51.9 million people watched at least 15 minutes of the BBC's Olympic broadcasts during the fortnight-long sporting contest, making it probably the country's biggest national TV event.
Last night's spectacular closing ceremony - featuring performances by acts such as Take That and the Spice Girls - drew a peak audience of 26.3 million viewers on BBC1 and across BBC digital channels.
An average of 23.2 million was watching the three hour-plus show - created by artistic director Kim Gavin - amounting to four-fifths of TV viewers.
It was a whisker away from the 23.4 million who watched the opening ceremony a fortnight earlier, put together by movie director Danny Boyle. The figure for Boyle's acclaimed extravaganza now includes an extra million digital viewers which the BBC initially failed to include.
Last night's event culminated with a breathtaking fireworks display and the flame in the cauldron being extinguished. It set a new audience record for Olympic closing ceremonies, easily outstripping the previous high of 11 million for Barcelona in 1992.
The figures crown a series of huge audience figures achieved during the Games, for the ceremonies and the colossal achievements of the athletes.
The biggest blockbuster among the sporting events during the London 2012 fortnight was Usain Bolt's triumph in the 100m final a week ago with 20 million tuning in, while 17.1 million watched Mo Farah take the 10,000m gold.
Tom Daley's bronze-winning performance during the 10m platform final on Saturday night pulled in 15.9 million.
BBC1 controller Danny Cohen said: "It has been an absolute privilege to broadcast the London 2012 Olympics on BBC1.
"It's been a phenomenal Games and Team GB's amazing achievements have helped draw huge audiences to BBC1 and put the channel right at the heart of the action.
"We've had fantastic feedback about the quality of the BBC's coverage and all the teams involved deserve huge thanks and praise."
The closing ceremony also featured Ed Sheeran covering Pink Floyd's Wish You Were Here, with a high-wire artist above the stadium recreating the cover image for the band's 1975 album. Annie Lennox, George Michael, Madness and One Direction were also among the performers.
The Beijing Olympics in 2008 drew an average of just 5.5 million, despite being screened on a Sunday afternoon.