Roache was born in Manchester, the son of Coronation Street actor William Roache and actress Anna Cropper. Roache was educated at Bishop Luffa Church of England School in Chichester, West Sussex and at the independent Rydal School in Colwyn Bay, North Wales, and married Rosalind Bennett in Malvern, Worcestershire in 2002.

In 1975, Roache appeared in Coronation Street playing Peter Barlow, the son of his father's character Ken Barlow. Roache is also a past member of the Royal Shakespeare Company.

Beginning in the 1990's, Roache began a career in film while remaining active in television and stage. He is best known to US audiences as Dr. Thomas Wayne, father of Batman, in Batman Begins (2005), or as Executive Assistant District Attorney Michael Cutter on the American TV series Law & Order (2008).

In June 2010, it was announced that he will reprise his first television role, alongside his father William Roache, in Coronation Street.

Roache was recently cast in the new HBO pilot The Miraculous Year.