Stewart started his rugby career at Ballymoney RFC Mini Rugby before progressing to Dalriada School and then to Ballymena Academy.
Recognition of his skills was rewarded with representative honours for Ulster under 18s against Leinster and Connaught, and Ulster under 19s against Leinster and Munster.
Following his Ulster duties, he represented Ireland Schools against England, Wales and Italy, and trained with the Irish Schools for the 2017 season.
At the start of the 2017/18 season, he represented Ulster Academy against Leinster, becoming the first schoolboy to do so. He also represented Ulster A against Llanelli.
In August 2018, Moore was named at 13 for Ulster's 2018/19 pre-season friendly against Gloucester and was included in Ulster's Champions Cup Squad for the season
Moore continued into his second season as an Ulster Academy player for the 2019/20 season.
|2018 - present|
|2019 - 2020|