Smart was born and educated in Adelaide where he worked as an Art teacher. After departing for Europe in 1948 he studied in Paris at La Grande Chaumière, and later at the Académie Montmartre under Fernand Léger. He returned to Australia 1951, living in Sydney, and began exhibiting frequently in 1957. In 1963, he moved to Italy. After a successful exhibition in London, he bought a rural property called “Posticcia Nuova” near Arezzo in Tuscany. He resided there with his partner until his death.