The pair suffered a very public falling out after Cole was axed from the judging panel of Cowell's US version of the show back in June.
The media mogul has continually attempted to mend their relationship in the subsequent months and, according to The Mail On Sunday, finally persuaded Cole to agree to a dinner date this week.
"Simon invited her for dinner," a source claimed. "He did all the running - he was much more upset about their friendship breaking down than he let on.
"He had been trying to persuade her to meet up for weeks. They talked about the sacking and Simon explained why it happened, and apologised for the first time. Simon has told Cheryl he wants to work on future projects together."
The insider further claimed that Cole appeared to be much happier since having the chance to reconcile with Cowell.
"Cheryl is playing it cool but they are friends again," they said. "She hasn't felt this great in months."
Cole was this week rumoured to be negotiating a big-money deal with ITV which would see her land her own chatshow.
Watch Cheryl Cole in the video for 'Promise This' below: