He exhibited from 1886 to 1895 at the Royal Society of British Artists and at the Royal Academy.
In 1891 he returned to Canada to stay, opening a portrait studio in Toronto.
Grier won recognition and admission to the Royal Canadian Academy of Arts becoming its president in 1929.
He painted numerous portraits of politicians, corporate leaders and other notable contemporaries, his first commissioned portrait being in 1888 and his last in 1947.
In 1935, he was made a Knight Bachelor by the government of Richard Bedford Bennett.
In 1937 he was elected into the National Academy of Design as an Honorary Corresponding Academician.