Morton was born in Glasgow, working briefly at a lawyer's office before studying at Glasgow School of Art. After attending Slade School, London, he studied in Paris under Gustave Boulanger and Jules Joseph Lefebvre. He was a member of the Glasgow Boys, and focused mainly on landscape painting. He later taught landscape painting at Glasgow School of Art, and in 1908, he was appointed Keeper of the Scottish National Gallery in Edinburgh. In 1925 he became Curator of Kirkcaldy Gallery of Art, where he died in 1928.