Grew up in Larne, County Antrim, Northern Ireland. Mickey Mason first began acting at the age of 14 while at high school, playing various roles in school pantomimes. He spent a lot of time in hospital from a young age. It was there that he learned to use different accents whilst performing puppet shows for the other children in the ward. His first television appearance was in an episode of 'Blue Peter' at 10 years of age. He joined different theatre groups, involving himself in and around various stage productions. He was a boxer for years, and fought in the County Antrim and Ulster championships. Mickey joined the National Youth Theatre in London, and in 2008, he was cast in his first television role by producer and director Lawrence Gough, as killer Daniel Young in an episode of Stirling productions television series 'In Cold Blood'(2006).