The X Factor judge, 31, revealed the surprise news on Sunday night by posting a picture of her engagement and wedding ring.
"I usually do not discuss my personal life but to stop the speculation I want to share my happy news... Jean-Bernard and I married on 7/7/14..," read the text accompanying the picture.
"❤️ We are very happy and excited to move forward with our lives together.."
Simon and Cheryl first met when Cheryl joined Simon's hit ITV show The X Factor in 2008. They famously fell out when Cheryl was fired from the US version after only several audition episodes, but the pair both admitted they were returning to the UK show early in 2014.
Cheryl posted a snap on Instagram of her jokingly wringing Simon's neck to announce the news.
"GUESS WHAT!!.. 😱 I'm baaaacccckkkkk!!!! #iMayActuallyRingHisNeck😊 #XFactor2014 👊 #leggooo 🙅" she captioned the shot.
In her first interview after announcing the news Cheryl said that it was Simon's constant begging that convinced her to return to The X Factor.
"There's only so much begging one can take," Cheryl said during an interview on Daybreak. "It's not nice to see a grown man cry, so I finally succumbed."
And the new dad again admitted that he had made a mistake in sacking her. "You know what, I've been doing this for a long time. You have fallouts. I held my hands up and said I was sorry, and I was sorry," he said.
"And then when I decided I wanted to come back (to the UK X Factor), I also decided I had to have Cheryl back on the show with me."