The actors were first linked in June (11), after Reynolds' motorcycle was spotted outside Theron's Hollywood home.
Representatives for the South African beauty fuelled the claims last month (Jul11) by refusing to confirm or deny she was dating Scarlett Johansson's ex-husband, but it appears the romance has already fizzled out.
According to Us Weekly magazine, Reynolds called off the fling in late July (11).
A source says, ""They're both too busy. And they were hardly ever together anyway.""
Reynolds' divorce from Johansson became official on 1 July (11).