The show, developed with Simon Cowell’s Syco company, saw an average audience of 17.2 million for the Sunday night final, a record for the show. The audience peaked at 19.4 million when ITV grabbed a 60% share of all viewing.
The broadcaster saw an average audience of 14.1m for the Saturday show on ITV1 and ITVHD, and the biggest ever Saturday night audience for The X Factor.
The Saturday night saw a peak viewing figure of 15.4 million and ITV took a 53% share of TV viewing.
Observers have suggested that ITV and Syco earned advertising revenue in the region of £25m for 30 second spots in the final weekend. Advertisers in the final show included Waitrose, BT and Apple.
The show, won by Matt Cardle, is sponsored by Talk Talk.
ITV had a strong week with the celebration of the 50th anniversary of Coronation Street and The X Factor finale.
However, industry observers have said that the broadcaster is overly-reliant for revenue on these shows and needs to develop new properties with rights that it can exploit internationally.
Chief executive Adam Crozier, who joined at the start of the year, has stated that the company needs to broaden its programming, although argues that investment is being held by the Contract Rights Renewal restrictions placed on ITV.