Sean Stewart scored for Norwich's Under-18s in a 6-2 win over their Watford counterparts on 20th July 2019. Stewart had joined the Under-18s for the 2019/20 season
he was called up for a Northern Irish Under-17 training camp in September 2019.
He made his Northern Ireland Under-21 debut on June 2nd 2021 against Scotland.
On 5th August 2023 he was loaned to Northern Irish side Cliftonville for the 2023/24 season. They are managed by former Ipswich midfielder Jim Magilton. Stewart had made 27 appearances for Norwich's Under-21s at the time of the loan.