So far their relationship is very casual but she's a big fan of him...
The New Yorker's David Denby called his performance "extraordinary" and compared him to a "stallion".
O'Connell has followed one extraordinary performance with another in '71, the debut film by director Yann Demange (another British TV graduate).
So I don't really think that Starred Up was that big an achievement for me. Michael Caine shouted "star of the future" at him on the set of Harry Brown back in 2009.
Physically and perhaps dramatically, but in terms of challenging me as an actor and really defining myself and pushing my own boundaries, not really."If British TV acts like a talent factory, churning out pretty young faces to fill our small screens and front pages, it also acts as a training ground for actors with something genuinely exciting to offer both the small and big screen. But it wasn't until his violently intense, heartbreaking portrayal of an aggressive but vulnerable young prisoner, Eric Love, in Starred Up that critics began heralding the arrival of a leading man with a potential for Brando-level intensity.
Back in 2009, he was one of a cast of unknowns entering the third series of Channel 4's teen-acting-talent production-line, Skins.
Now, the 24-year-old Midlander is the leading man in Angelina Jolie's latest directorial project, and on first-name terms with Brad Pitt.