"Brad and Charlize have known each other for years and recently became even better friends after working together," a source told Entertainment Tonight on Tuesday. "They enjoy each other's company and connect on many levels. Brad and Charlize have a lot of mutual friends and share their love of acting, but neither of them are ready for a serious relationship right now."
"They are both very single at the moment so it's no surprise people are talking romance. They truly would make a Hollywood power couple, but at this point, they're friends," the source continued, adding that when Pitt does settle down again, he won't be "looking for an actress as a lifetime partner."
"He's tried that route already, and while he loved both Jen [Aniston] and Angelina [Jolie] very much, and he grew tremendously as a person with both women, he is ready fo something different. At the moment, he is all about his career and his children. He is working on several projects and spends every moment he can with his kids," the source added.
A different source told PEOPLE that despite Pitt and Theron working on a project together six months ago, they have not been in contact since.
"About six months ago, they did a shoot together," the source said. "They have not been out together recently, and were never dating. Reports of them being involved romantically are false."
The shoot in question may be an ad for watch brand Breitling, which Pitt, 55, and Theron, 43, did with Adam Driver.
PEOPLE's source added that the Sun's claim that Theron's ex, Sean Penn, introduced them, "couldn't be more false. Not in the slightest."
In the wake of his divorce and custody battle with ex-wife Angelina Jolie, Pitt has kept a low profile in the dating scene. He was linked to MIT professor Neri Oxman in mid 2018, though she later denied a romantic relationship with the actor.
Pitt and Jolie finally agreed to a custody agreement in November over their six children: Maddox, 17, Pax, 15, Zahara, 14, Shiloh, 12, and 10-year-old twins, Vivienne and Knox.
Theron and Penn split in 2015, calling it quits on their engagement. She has remained single since.