A source told The Sun of the "World War Z" actor and Oscar winner Theron, "They have been casually seeing each other for nearly a month now. They've been friends for some time — ironically through Sean — but things have developed."
Spies claim the couple got cozy last weekend after Pitt, 55, hosted a screening of "If Beale Street Could Talk" and Theron, 43, was a guest of honor at a "Roma" event at Los Angeles' Chateau Marmont.
"Brad came over to Chateau afterwards, changed his outfit and joined Charlize in a corner of the bar," an insider claimed. "She was on a vodka cocktail while he stuck to mineral water. They were ridiculously touchy-feely and his arm was around her back. At one point he winked at her."
The source added, "Brad seemed in a really good place — they both looked really happy."
Jolie, 43, and Pitt reached a custody agreement in November 2018 after battling one another over their six children for more than two years.
Theron's last public romance was with Penn, 58. They called off their engagement in June 2015.
Reps for Theron and Pitt did not immediately return Fox News' requests for comment on the romance rumors.