Charlie Thomas Cox was born in London, England, to Patricia C. A. (Harley) and Andrew Frederick Seaforth Cox, a publisher. He has English, Scottish, and Irish ancestry, and descends from several prominent forebears (Baronets of Agnew and Carnegie, an Earl of Findlater, and a Colonial Governor of New York, Andrew Elliot).
Cox was educated and received his training in drama at Sherborne School in Dorset where he appeared in Dealer's Choice / Patrick Marber (Mugsy) The Writing Game (Leo) Code Crackers / Andy Wilkinson (Weasel) Confusions / Alan Aykbourne (Martin & Arthur) Henry V (Nym & John Bates). He received the Gerald Pitman Award for Acting from Sherborne School. He also appeared in the BBC production of Judge John Deed as the Young Vicar.
He starred in Things To Do Before You Are 30 (formerly You Don't Have To Say You Love Me), with Dougray Scott, The Merchant of Venice, with Al Pacino, and Dot the I (aka Obsession) with Gael Garcia Bernal, which received rave reviews at The Sundance Film Festival.
Charlie lives in London with his brother.