Boardman was born in Stockport, England. He attended Reddish Vale High School in Stockport. Boardman then graduated from the Oxford School of Drama and is married to his former Coronation Street co-star Jennifer James. They have one son, Jack Alexander, born March 2004 and a daughter, Scarlett Marie, born April 2010.
His BBC series Drop Dead Gorgeous won Best Comedy Drama at the British Comedy Awards 2008.
He is best known for playing Murray Priestman in Drop Dead Gorgeous as well as the drug dealer Jez Quigley in Coronation Street. He appears as Timon the Jew in the television series Rome. He also made an appearance in the fifth episode of the 2011 BBC crime-drama series Death in Paradise. In 2013 he starred in the ITV1 comedy drama series Great Night Out as Hodge. In 2014 he played the recurring character of Amerigo Vespucci in Da Vinci's Demons.
In 2013 Boardman and James launched Actor Tribe, an acting school for children.