Hugh MacInnes was born on 3rd June 1893 in Edinburgh, Scotland to Hugh and Flora MacInnes. He was the fourth out of five children, for he had three brothers and one sister. Later, the family moved to Oban, Argyllshire where his father worked as a ferryman. After living with his family in Scotland, in 1911, Hugh emigrated to Quebec on 29 September leaving from Liverpool on the Empress Britain. By 1914, High was living in Winnipeg, Canada, where he was working as a banker.

It was while he was living in Canada that the war broke out and he enlisted in the Canadian Overseas Expeditionary Force on 17th April 1916, aged 22, at Winnipeg. He served with the Canadian Infantry, 78th Battalion (Manitoba Regiment).

Hugh was killed in action during the Second Battle of Passchendaele (26 October - 10 November 1917), during the Canadian advance to the village. While at the front line during operations, he was wounded behind his left ear by shrapnel. He made his way to a dressing station, where he was instantly killed by an enemy shell.