The Lyndsey Turner-helmed production will run at the Barbican Theatre.
The musical features the Academy Award-winning music and lyrics of Glen Hansard and Markéta Irglová.
WhatsOnStage.com had 20 questions with the stage and screen star. Take a look at what she had to say.
Mangan last appeared on Broadway in 2009 in his Tony-nominated role in The Norman Conquests.
Berry Gordy's hit musical may make a trip across the pond.
Richard Fleeshman and Jenna Russell star in the soon-to-open St. James Theatre production.
The production will close after three months.
The hit 1985 film plans to hit the West End in time to celebrate its 30th anniversary.
Nominees for the 2014 WhatsOnStage Awards will be announced December 6.