And adding further fuel to the fire, the reported couple were pictured out and about in Los Angeles on January 23 - albeit separately.
South African-born Charlize, 43, looked typically chic in a laid back black ensemble and Christian Dior tote bag for a late meal at celebrity hotspot The Brig.
Just hours before, 55-year-old Brad was spotted in high spirits while scoping out a new business venture in the same area.
The pair, who have known each other for years through mutual industry pals, reportedly grew close while working together on a recent photo shoot for Breitling watches.
Other reports suggest the talented couple were introduced by Charlize's ex, fellow actor Sean Penn.
But despite widespread reports, an inside source tells Entertainment Tonight the stars are simply good friends.
'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,' adding that rumours of romance are no surprise given the single status of both actors.
If confirmed, Theron would be Pitt's first public relationship since his high profile divorce from longtime love Angelina Jolie.