The X Factor final last night was down four million viewers on the previous year, figures showed today.
The ITV1 programme had an average audience of 13.1 million, compared to the 17.2 million who watched as Matt Cardle triumphed in the 2010 competition.
And it was the lowest average audience for the finale of the series since 2007, when Leon Jackson won the show.
Last night's peak audience for The X Factor - which has been down on the previous year throughout much of the series - was also four million fewer, drawing 15.5 million at its height.
ITV drew comfort from the series being the third most successful in The X Factor's eight-year history. The final helped to boost the series average up to 11 million viewers across the 17-week run.
ITV pointed out that BBC One rival Strictly Come Dancing had averaged 9.7 million viewers this series.
The semi-final of the dance show had a higher audience than the first leg of X Factor's final on Saturday night.
But the Sunday night finale of the ITV1 series - in which Little Mix took this year's honours - was two million viewers ahead of Strictly's results show, which had an average of 10.9 million.
In 2009, the final edition of The X Factor pulled in an average 15.5 million - equal to this year's peak, while in 2008 it drew 13.2 million.