McInnes was born in St Kilda, a suburb of Melbourne, to Malcolm McInnes and his wife Alice Agnes, née Beckwith. Despite lack of family artistic tradition, he was keen to draw from the time he could hold a pencil. In 1903, at 14 years of age, he enrolled in the drawing school of the National Gallery of Victoria under Frederick McCubbin. Later he moved up to the painting school under Lindsay Bernard Hall.
