Dornan, 31, replaces Sons of Anarchy's Charlie Hunnam, who dropped out of the project more than a week ago. Ben and Kate's Dakota Johnson will portray Christian's younger love interest, Anastasia Steele.
Dornan tested Friday opposite Johnson, as did Tony-nominated actor Billy Magnussen, according to THR. The race to fill Hunnam's shoes began immediately after he dropped out, since Fifty Shades of Grey is slated to begin production on Nov. 1. The film is scheduled to hit theaters on Aug. 1, 2014.
It remains unclear how Fifty Shades fans will react to Dornan's casting. After the two main roles were first filled in early September, an online petition was started to have them replaced with Matt Bomer and Alexis Bledel.
In addition to his recurring role on Once, Dornan stars in the U.K. series The Fall and also appeared in Marie Antoinette. He is also known for having dated actress Keira Knightley, whom he met at a photo shoot in 2003. They were together for two years before splitting.
What do you think of Dornan's casting?