The Black Hawk Down star's girlfriend Tamsin Egerton is expecting the couple's first child, his representative has confirmed to the editors of the New York Post's Page Six column.

The spokesperson tells the outlet, "It’s true and they are beyond thrilled."

The actor has been dating Egerton since 2012 after meeting on the set of The Lovers.

Hartnett has a long list of famous exes, including his O co-star Julia Stiles, Amanda Seyfried, Amber Sainsbury and Scarlett Johansson, while he has been linked to supermodel Helena Christensen, Kirsten Dunst and Mischa Barton.

Egerton previously dated The Chronicles of Narnia: Prince Caspian star Ben Barnes.

No details about the sex of the baby or when it's due have been released.