The 30-year-old singer ended his relationship with American beauty editor Halle Carlson to focus on the ITV1 show, The Sun reports.
Sones is said to have told friends that he believes he ruined his chances of a date with Cheryl Cole by telling her he had a girlfriend while at Judges' Houses.
"Halle supported him all the way to Boot Camp. But Kye thinks X Factor will change his life forever and it's given him the push he needed to end the relationship," a source said.
"If he had a second chance with Cheryl, he'd jump at the chance."
An X Factor spokesman confirmed the split, adding that the former couple "remain good friends".
Watch Digital Spy's interview with X Factor's Overs category below: