Akinnuoye-Agbaje was born in Islington, London. His parents are Nigerian, of Yoruba origin. He has a law degree from King's College London and a Masters in Law from the University of London. He is fluent in several foreign languages including Yoruba, Italian, and Swahili. He can "get along" in a few other languages, including French.
His best known acting roles have been as the imposing convict Simon Adebisi in the 1990s HBO prison series Oz, and as Mr. Eko on ABC's survivor drama Lost. He was also in an episode of New York Undercover. He has numerous film credits since he began acting in 1994 and has appeared in many top films, including The Bourne Identity, in which he played a deposed African dictator, Hitu the police officer in Ace Ventura: When Nature Calls, Lock-Nah in The Mummy Returns, and Heavy Duty in G.I. Joe: The Rise of Cobra.