Opening its doors for Kerry Katona, Tara Reid and Jedward among others, the revived reality show - now hosted by Brian Dowling - premiered with 5.16m (22.3%) between 9pm and 10.30pm.
Celebrity Big Brother's strong performance, peaking with 5.6m (26.1%) at 10pm, makes it Channel 5's fourth best broadcast since the network's inception in 1997.
Emma Willis's Big Brother's Bit on the Side followed the main show with 1.82m (13.4%) until 11.30pm.
Despite expectations that the programme's popularity would lessen on Channel 5, the ratings compare well to Channel 4's respective 2010 and 2009 launches.
More Celebrity Big Brother launch night coverage:
> Celebrity Big Brother on Channel 5: Hit or flop? - poll
> Celebrity Big Brother launch night: Live blog
> Digital Spy tours the house - video
BARB ratings data supplied by Attentional