Deadline confirms that Braga has been cast in an unknown role in the project, which will be Blomkamp's follow-up to District 9.
The director has yet to announce any plot details for Elysium, only confirming that it will be set in the far future on another planet.
Braga will now join the likes of Matt Damon, Jodie Foster and District 9 star Sharlto Copley in the film's cast.
Braga has appeared in a number of films including Predators and I Am Legend, but most recently starred opposite Sir Anthony Hopkins in The Rite.
Elysium is currently expected in cinemas on March 1, 2013.