The 60-year-old star thinks the Take That singer - who is a judge on 'The X Factor' UK, the same pop star search show on which she used to mentor - is a real hunk and she would love to get him into bed.
In an interview with the new issue of heat magazine, she said: ''I'd definitely like to have sex with Gary! He's very attractive! I think he needs an older woman.''
Sharon still keeps track of what's happening on 'The X Factor' and although she loves looking at Gary, 41, she thinks the programme misses its creator Simon Cowell, who is currently judging the American version of the series.
She revealed: ''It's a very, very different show without Simon. I think he'd like to come back. He misses the UK a lot, and let's face it, he is 'The X Factor'.''
Meanwhile, Sharon - who is married to rocker Ozzy Osbourne - has revealed her daughter Kelly has become broody since her brother Jack and his wife Lisa welcomed their daughter Pearl into the world in April.
Kelly is in a relationship with vegan chef Matthew Mosshart and Sharon believes it's only a matter before the couple make a bigger commitment to each other.
Sharon - who is judging new British reality TV show 'That Dog Can Dance' - said: ''I think Kelly wants to end up with 10 babies. One day it will definitely happen. You can't help but feel broody when you see that little butterball - you just want to eat her up! Kelly's so happy she could get married tomorrow ... Matthew is a lovely guy.''