He was born to parents from the Brong Ahafo Region,[2] and moved to Hertfordshire, England, with his father, Peter Osei Mensah,[3] an architect engineer, his mother, a writer, and two younger sisters at a young age.

Mensah's film credits include Avatar, 300, Hidalgo, Tears of the Sun, Jason X, Harvard Man, Bless the Child and The Incredible Hulk.

He also stars in the short film The Seed, produced and directed by Linkin Park's DJ Joe Hahn.

He has made television appearances in Star Trek: Enterprise, Tracker, Witchblade, Blue Murder, Relic Hunter, Earth: Final Conflict, Highlander: The Raven, and La Femme Nikita.

He was a member of the repertory cast of the A&E Network series A Nero Wolfe Mystery and Terminator: The Sarah Connor Chronicles.