He was born in Edmonton in 1916, and spent most of his life in Alberta. O'Hanlon was fascinated with the Native American way of life and lived for several years on a Native reservation in Montana, but his immense knowledge of early Native American customs comes from research he did mainly at the Glenbow Foundation in Calgary. He had no formal instruction in either painting or sculpting, and before he started working in bronze, he expressed his interest in the Blackfoot people and their culture through his oil paintings, completing over 50 portraits in all. Several are owned by the Glenbow Museum. Others are in private collections in Canada.