Matt Damon as Jason Bourne: an amnesiac assassin out of Paris who is being pursued by his former employers. Main protagonist.
Franka Potente as Marie Helena Kreutz: an Bohemian German traveller down on her luck, paid by Bourne to transport him to Paris and who eventually ends up helping Bourne find his past.
Chris Cooper as Alexander Conklin: the coordinator of Treadstone and Bourne's immediate superior, he is tasked with dealing with the fallout of Bourne's rogue status and covering up the growing problem.
Brian Cox as Ward Abbott: a CIA Deputy Director and Conklin's immediate superior.
Julia Stiles as Nicky Parsons: a CIA field operative working in Paris who reports to Conklin.
Clive Owen as The Professor: a Treadstone operative based out of Barcelona who is dispatched to locate and kill Bourne.
Adewale Akinnuoye-Agbaje as Nykwana Wombosi: a deposed African dictator who seized power with backing from the CIA and threatens to reveal the names of those who assisted him if he is not given aid to retake his former position of power. Was Bourne's last target prior to his amnesia.
Gabriel Mann as Danny Zorn: Conklin's assistant and a key member of Operation Treadstone's control team.
Nicky Naude as Castel: a Treadstone operative based out of Rome sent to kill Jason Bourne.
Russell Levy as Manheim: a Treadstone operative based out of Hamburg sent to kill Jason Bourne.