John was educated at James Gillespie's High School, Edinburgh.
John has previously dated Catherine Zeta Jones and Abi Titmus.
John is 6'5" (1.96 m) tall.
John: (Talking about former partner Abi Titmus' fame after the two seperated) Nobody was more surprised than me when she went off and did what she did. She took the chance, and you've got to admire her for it. I don't think Celebrity Love Island was a good idea. But up to that point she was playing a good set of cards.
John Leslie: (Talking about former partner Catherine Zeta Jones) She was stunning. The most beautiful woman I'd ever seen. There was nothing to compare to her. We talked and there was a lot of yin and yang and mutual attraction.