X Factor judge Sharon Osbourne has admitted to having a secret fling with Jay Leno.

The 60-year-old star revealed that she had a two-month romance with the US chat show host before she began dating Ozzy Osbourne, her husband of 31 years.

She spilt the beans on her US show The Talk, where she claimed that she "wasn't very dateable" after moving to America in the late 70s.

"Remember, at 25, I had met my husband but we weren't together. We were just friends," she told the panel.

"So, I'm here, [and] I didn't have a boyfriend -- I never did date a lot at that time anyway because I was not very dateable."

She went on to reveal that she got close to Leno after encouragement from a friend.

"My friend worked at this place and she said 'you have to come down because it's full of men'. I came down and it's full of men performing. And this one person, I think 'oh, he's very nice, very funny'.

"So my friend goes, 'I've got his number'. So we prank called him and he liked my voice. Then I kept calling.

"One thing led to another and he actually came round to my house and met me. And then we had a little fling."

According to Osbourne "the fling was more fling for me and not fling enough for him because a couple of months into it, he brought around the real love of his life for me to meet. And she was lovely.

"They were so kind to me and continued a friendship over the years."

When co-host Julie Chen asked if she had ever had sex with Leno, she replied: "It was so long ago, I can't remember."

However, when pushed for an answer, she added: "Yes, yes."

Leno married now-wife Mavis Nicholson in 1980 and Osbourne wed Black Sabbath rocker Ozzy, 64, in 1982.