Born in Brantford, Ontario, Harris studied at the University of Toronto (1903) as well as in Berlin, Germany under Fritz von Wille, Adolph Schlabitz and Franz Skabina (1904-1907). He then traveled and painted in Austria, England, France, Italy, Palestine (1909) and Minnesota before returning to Toronto in 1910. He began painting in Northern Ontario in 1912 exploring areas in Algoma, Haliburton, and Lake Superior (1921). His later painting trips took him to the Laurentians of Quebec, Nova Scotia, Newfoundland (1921), the Rocky Mountains (1924), the Arctic (1930), New Hampshire (1934-1939), and Santa Fe, New Mexico (1939-1941) before settling in Vancouver in c. 1940 where he died. Working in oil, watercolour, pencil and ink, his early streetscapes and houses show the influence of Impressionism (1911).
After 1913, his landscapes because influenced by Art Nouveau and by the Scandinavian paintings he saw in an exhibit in Buffalo, NY. Under the influence of Wassily Kandinsky and with his interest in Theosophy in the 1920’s, Harris’s landscapes because increasingly more simplified and abstracted (1937). He sought spiritual values in nature and revealed them in his work. He also painted several portraits. He was a member of the Toronto chapter of the International Theosophical Society (1923), a founding member of the Group of Seven, first President of the Canadian Group of Painters, and President of the FCA. Harris received honourary doctorates from UBC, University of Toronto, and the University of Manitoba, and a Canadian Council medal in 1961. He was made a Companion of the Order of Canada in 1970 and his work is in the collections of the AGH, AGO, EAG, GM, MCMC, MMFA, NGC, VAG and WAG.