It was the most-watched programme of the night by more than four million viewers, drawing an audience share of 47 per cent. The show had an average audience of 9.3 million between 8pm and 9.25pm across ITV, ITV HD and ITV +1.
The latest series features the return of Simon Cowell and Cheryl Fernandez-Versini alongside new judge Mel B and the UK show's longest-serving judge, Louis Walsh.
Doctor Who was the next most-watched programme with 5.2 million tuning in for the latest episode between 7.30 and 8.15pm across BBC One and BBC One HD.
Viewing figures dropped for the Sunday evening show, which hit a peak of 9.4 million, representing a 38 per cent audience share. The hour-long show had an average audience of 8.2 million, a 32.1 per cent share.
Despite not matching the viewing figures of Saturday’s launch show it was still easily the most-watched programme on Sunday evening.
Next week The X Factor faces stiffer competition on Sunday evening when BBC 1’s Strictly Come Dancing opens its new series.