Theo James was born on December 16, 1984 in Oxford, Oxfordshire, England, United Kingdom as Theodore Peter James Kinnaird Taptiklis. He is an actor, known for his role as Tobias "Four" Eaton in the films Divergent (2014), The Divergent Series: Insurgent (2015) and Allegiant (2016). He is also known for his roles as David in Underworld: Awakening.

Graduated high school from Aylesbury Grammar School and then studied at the University of Nottingham, receiving a degree in Philosophy. He trained at the Bristol Old Vic Theatre School.

He is the son of Jane (nee Martin) and Philip Taptiklis. He is of one quarter Greek descent, with the rest of his ancestry being English and Scottish. His paternal grandmother, Barbara Jean Dorothy (nee Keech), was born in West Derby, England and had one quarter of a German ancestry, and his paternal grandfather, Nicholas Theodore Taptiklis, was born in Greece; they moved to New Zealand, where Theo's father, Philip, was raised. Theo's mother's family is from Glasgow, Scotland.