Johnston was born in Sunridge, Ontario. During the Second World War, Johnston served as a Major in
The Algonquin Regiment, a light infantry regiment which saw action in Normandy, northern France and Belgium. After the war, he rose to become Lt. Colonel of the Regiment. After the war, Johnston established an insurance company in South River, W.A. Johnston Insurance, which is still operated by his two sons. He was active in a wide variety of charitable organizations, including serving as President of the local branch of the Royal Canadian Legion. ==Politics==