Deadline reports that the Independence Day star will play psychotic murderer Oswald Jones in the ten-part run.
A dangerous and clever criminal, the character will escape his prison sentence and become involved in a worldwide crisis.
Pullman's film roles includes appearances in Sleepless In Seattle, Casper and The Killer Inside Me. He also starred in NBC mini-series Revelations and made a guest appearance in a 2008 episode of Law & Order: Special Victims Unit.
Torchwood: The New World will air on BBC One in the UK and Starz in the US.