Stewart trained at the National Screen Acting School of Ireland, Bow Street. Upon graduating, he was cast in the theatre production of 'Mind Games' with Spanner in the Works Theatre Company; touring Ireland, the UK and the United States in the leading male role of 'Art'.

Stewart was one of the last 10 actors selected for Filmbase Ireland's 'Close Up': Professional Actor's Talent Development scheme in 2017 before its closure in 2018. He was also an Arts Club Theatre Company Actor's Intensive Selectee 2022 in Vancouver, Canada. Stewart has trained under the guidance of renowned acting coaches Gerry Grennell and Andrew McIlroy, in both Ireland & Canada respectively. He holds a degree in Film & Media.