[5] That year he began his first training as an artist at the Hamilton Art School,[1] where he studied under John Ireland and Arthur Heming.

He continued his training at the Central Ontario School of Art and Design, where he studied with George Agnew Reid and William Cruikshank.

[3] Whilst at Carlton, he worked with Norman Mills Price, William Tracy Wallace, and Albert Angus Turbayne.

In 1911, MacDonald resigned his designer position at Grip Ltd. and moved with his wife and child to Thornhill, Ontario, to pursue a career as a landscape artist.

[3] After developing his own style as a painter, he organized a show of his work at the Arts and Letters Club of Toronto in November 1911.

Though derided by art critics of the day, it was a fairly conventional post-impressionistic painting of sunflowers—one that recalls Vincent van Gogh's treatment of the subject from nearly forty years before, but in which MacDonald would have relied on sketches of sunflowers he made in his own garden at Thornhill, Ontario.

The group would hitch their car to trains travelling through the area, and when they found a scenic location, they would unhitch and spend time exploring and painting the wilderness.

[6] These trips would produce some of his most acclaimed paintings, including Mist Fantasy, Sand River, Algoma (1920) and The Solemn Land (1921), elegant works that are meditations on his longtime experience in design combined with fiery colour.

[12] The other founding members were Frederick Varley, A. Y. Jackson, Lawren Harris, Frank Johnston, Arthur Lismer, and Franklin Carmichael.

From 1928 until his death MacDonald served as the Principal of the Ontario College of Art, and he painted with less frequency and less consistent success.