Roache was educated at Bishop Luffa School in Chichester, West Sussex and at Rydal School. He studied acting at the Central School of Speech and Drama.
In 1975, Roache appeared in Coronation Street playing Peter Barlow, the son of his father"s character Ken Barlow. Beginning in the 1990s, Roache began a career in film while remaining active in television and stage. In 1994, he received acclaim for his leading role in Antonia Bird"s Priest.
His first breakthrough role was as Doctor Thomas Wayne, father of Batman, in Batman Begins (2005), or as Executive Assistant District Attorney Michael Cutter in the American television series Law & Order (2008–2010) and Law & Order: Special Victims Unit (2011–2012).
In June 2010, it was announced that he would return to play Laurence Cunningham, alongside his father William Roache, in Coronation Street. In July 2010, he was cast in the Home Box Office pilot The Miraculous Year.
In April 2011, Roache was cast as the lead in the Independent Television mini-series Titanic, airing March–April 2012 to coincide with the 100th anniversary of the sinking of the ship. In February 2014, Roache debuted in season two of the popular television series Vikings as King Egbert of the Kingdom of Wessex.
Roache is also a past member of the Royal Shakespeare Company.