The son of Ronald C. and May Alicia MacDonald, Ross MacDonald attended public school in Winnipeg, St. Andrew's College in Toronto and the University of Manitoba. He was commissioned on 1 September 1916 and served with the 179th Battalion of the Cameron Highlanders before he transferred to the Royal Flying Corps in February 1917. In March 1917 he joined 15 Squadron as an observer and was frequently mentioned in dispatches. In 1918, after completing pilot training, he was posted to 87 Squadron as a Sopwith Dolphin pilot. Before he was shot down and captured on 29 September 1918, MacDonald downed 5 enemy aircraft. Later in life he operated Ross MacDonald and Co., manufacturers' agents. He died at Winnipeg General Hospital. He was 71.