Warwick was born in Broxbourne, Hertfordshire, and has had leading roles in UK TV including Agatha Christie's Partners in Crime (alongside Francesca Annis as the sleuthing couple Tommy and Tuppence), the detective series 'The Terracotta Horse' and the BBC serial The Nightmare Man. He also appeared in the Doctor Who serial Earthshock as Lieutenant Scott.
Other notable credits include: Jason King, The Onedin Line, Lillie (where he again acted with Ms Annis), Rock Follies, Tales of the Unexpected, Howards' Way, Bergerac and Iris Murdoch's The Bell with Ian Holm.
Warwick has also worked in American television, with guest star roles in Scarecrow and Mrs. King, Civil Wars, Home Improvement, Murder, She Wrote, Babylon 5 and Alias amongst many others.
James Warwick also was a voice actor in the 1999 hit computer game Battlezone II: Combat Commander. He played the character of General Armond Braddock. He has also voiced Qui-Gon Jinn in many Star Wars video games and the Cartoon Network series Clone Wars.
His starring theatre roles included An Ideal Husband on Broadway, and King Arthur in the US national tour of Camelot. He played Brad in The Rocky Horror Show on stage in London for the first year of its run in addition to many leading roles in the West End and in regional theatres across the UK and America.
Warwick is also an award winning theatre director, with credits from major theatres across the US. He served as associate artistic director at the Berkshire Theatre Festival and the Chester Theatre Company, as well as artistic director of the Colonial Theatre in Pittsfield, Massachusetts. He was Interim President of The American Academy of Dramatic Arts, Los Angeles campus 2007/8 and directed over a dozen productions for their Company series. In 2009, James Warwick was appointed President of Theatre of Arts, a College for the Contemporary Actor in Hollywood, California.