He was the son of Harry Hilton Stewart and Anna Mary Maude Stewart of Chattenden, Chichester Park, Belfast. The family were of of Church of Ireland faith. Harry's job was recorded as Bank Inspector. He worked for the Northern Bank.
Stewart joined Northern Bank on 5th October 1913 in Head Office. Transfers to Shaftesbury Square (1913) and Head Office (1914) followed.
In September 1914, he volunteered and enlisted into the Royal Fusiliers (Public Schools and Universities Bn.) as a Private with Service Number FS5676. He was promoted to Lance Corporal and then to Corporal. He served with the British Expeditionary Force ultimately ending up at the Somme (1916).
Stewart was serving with the 20th Bn. Royal Fusiliers when he was killed in action on 16th July 1916 aged 21.
Stewart was awarded the 1914/15 Star, the British Victory Medal and the British War Medal and he is commemorated on the Thiepval Memorial, France.
The Belfast News Letter of 25th July 1916 reports: