The X Factor UK judge is currently number one with debut solo single 'Young' and was last week named FHM's 'Sexiest Woman in the World' for 2012.
However, former Atomic Kitten singer Katona told Now magazine: "I don't know how to put it without being rude, but she doesn't have that star quality."
The reality TV star added: "There's something about her I just don't get!"
The Only Way Is Essex's Mario Falcone took to Twitter last week to question Contostavlos's poll victory, suggesting the N-Dubz singer's victory was a "fix".
Watch celebrities praise Tulisa's FHM win in our exclusive below: