The viewing high came towards the end of a live two-hour final, aired between 9pm - 11pm, which averaged three million viewers overall, representing a 14.2% audience share.
The figures complete a successful three weeks for Channel 5, which has averaged audiences of 2.9 million in its first outing with Endemol's 'Big Brother' franchise.
Nick Bampton, commercial director of Channel 5, told Media Week: "Last night's final tops off a phenomenal 'Celebrity Big Brother' for Channel 5. Lots of people doubted us but our audiences have held up really well throughout the series.
"Last night we grabbed 22.2% share of 16- to 34-year-olds, that's massive. One of the reasons why the show has been such a success is down to the support it has received across Northern & Shell's stable."
The viewing figures for 'Celebrity Big Brother' came despite a competitive night of TV viewing during the two-hour period (9pm-11pm).
Channel 4, the former home of 'Celebrity Big Brother' and the broadcaster behind 'My Big Fat Gypsy Wedding', which made a star of this year's winner Doherty, had to content itself with a peak of just 1.6 million for its US import 'The Killing'.
A Channel 4 spokesperson was keen to stress the role the broadcaster had played in 52-year-old Doherty's rise to fame with its groundbreaking programme about travellers in February. The spokesperson also highlighted the differences between the audience for CBB and the more upscale demographic attracted to 'The Killing'.
Elsewhere, ITV's stalwart soap 'Coronation Street' peaked at 7.3 million between 9pm-9:30pm and Simon Cowell's 'Red or Black?' hit highs of 4.5 million between 9:30pm and 10pm.
Outside the commercial channels, BBC One's audience during the same two-hour window peaked with 4.1 million viewers during 'Torchwood' shortly after 9pm.
Bampton said: "The final completed what have been fantastic audiences for 'Celebrity Big Brother' that will help reposition Channel 5 and build confidence around what we're capable of going forward."
Chris Locke, group trading director at Starcom MediaVest, agreed that 'Celebrity Big Brother' "has to be considered a success for Channel 5", despite being slightly down on the numbers of last year's 'CBB' final on Channel 4.
Aired at the end of January 2010, and won by Katie Price's partner at the time, Alex Reid, the previous 'Celebrity Big Brother' achieved highs of 4.5 million.
Speaking ahead of the regular 'Big Brother' show launching tonight, Locke said he believed the franchise could be a spring board for the broadcaster.
"Channel 5 needed a big show to make it famous, put it on the map and to give people a reason for tuning in, and 'Big Brother' could well be it," he said.
"It will help change the profile of Channel 5 into a younger, mass market audience that are attractive to clients [advertisers].
"You'd hope they'd create a better, smarter schedule around it next year to lock people in and help audiences migrate across its programming and also digital platforms.
He added: "The non celebrity version [tonight] could get off to good start with Pamela Anderson taking part, it should get some more men interested."