West was born into an Irish Catholic family in Sheffield, Yorkshire, England to George West, who owned a plastics factory, and to Moya, a housewife. West attended Eton College and Trinity College, Dublin for his education.

Dominic West attended Guildhall School of Music & Drama on a three year BA Honours Degree in Acting and graduated in 1995.

He made his debut in 1991 in a short called 3 Joes. His other screen appearances include True Blue, Chicago and Mona Lisa Smile. His most notable television role has been Baltimore police officer Jimmy McNulty on the HBO television police drama The Wire.

In film, he portrayed the heavy-metal guitarist Kirk Cuddy in the 2001 film Rock Star. In 2007, he played the Spartan politician Theron in 300. West also starred in the 1999 rendition of William Shakespeare's A Midsummer Nights Dream as Lysander.

As a theatre actor, West has appeared as Konstantin in the Peter Hall-directed The Seagull (1996) at the Old Vic. In 2005, he returned to the stage to play Orlando in David Lan's As You Like It at the Wyndhams's Theatre in London.

He played Edward in Harley Granville Barker's The Voysey Inheritance directed by Peter Gill at the Royal National Theatre in 2006. In late 2006 and early 2007 he played the lead role of Jan in Tom Stoppard's Rock 'n' Roll in London's West End. Dominic is slated to play the villain, Jigsaw, in the December 2008 movie Punisher: War Zone.