He will join Chris Pine, Zachary Quinto, Simon Pegg, Karl Urban, Zoe Saldana and Anton Yelchin in the sequel directed by Justin Lin.
Simon Pegg and Doug Jung have taken the writing duties, with early rumors saying that Klingons could be the main villains.
The J.J. Abrams reboot series started in 2009, with a sequel, Star Trek: Into Darkness, released in 2012.
Production on Star Trek 3 is set to begin in June.
Elba is known for his roles in Prometheus and Pacific Rim. He has been cast in the upcoming Harmony Korine film The Trap.
Lou Chase | Staff Writer