Jamie was born in Hammersmith, London in April 1973. He grew up in France, and his family moved back to the UK when he was 8. His father, Ralph, is from Detroit, Michigan and is a management consultant. His mother, Elizabeth, is from Northern Ireland, and trained as an actress. Jamie has five brothers and one sister. His parents divorced when he was twenty.
Jamie attended St. Paul's School in London and St. John's College, Cambridge, earning MA in Modern Languages. Jamie entered the London Academy of Dramatic Arts (LAMDA) in 1996. After his graduation he earned the role of Archie in the UK series Horatio Hornblower
, and he reached international audiences through his role as Apollo on the new Battlestar Galactica
Jamie is married to Kerry Norton, with whom he has 3 children: Isla, Darcy and Ava (twins).