Andrew Flanagan was raised in Easterhouse then Milton, Glasgow, Scotland by his mother Elizabeth after his father left at an early age. He is the youngest of five and is the brother of actor Tommy Flanagan. Andrew followed Tommy into acting in the early nineties after being offered the chance to work with innovative Glasgow theatre, television and film company Raindog Ltd. After a five year break to "get a real job and get married" he returned to acting in 2008 with a role in Nicolas Winding Refn's Valhalla Rising, (in production).