The singer, who will be shown performing for Mel B at this weekend's Judges' Houses, fancies Jessie J - and Ariana Grande!
Speaking ahead of his audition airing, he admitted: "Ariana Grande and Jessie J are my celebrity crushes. I love the way Jessie just owns it!"
Jack grew up in Yorkshire and is a fitness fanatic. In fact, he tries to fit in SIX gym sessions a week. Phew!
But although he realised he could sing aged eight, after his mum entered him into a karaoke competition, Jack is far from confident about his voice.
Speaking about his first audition in front of the judges, Jack admitted: "I wasn't going to go to be honest.
"I pretended my car broke down because I didn't want to go. I had massive self-belief problems at first."
Well you've made it to Judges' Houses, Jack, so you can't be too bad!