He made his stage debut in 1905 at Theatre Royal, Manchester in Frank Benson's company and went on with them to perform more than 200 Shakespearean roles.
He returned to theatrical work after the war making his American debut in 1922 in the world premier of George Bernard Shaw's Back to Methuselah.
Johnston created the role of Oscar Jaffe in the 1932 play Twentieth Century, which was later turned into a film and a musical.
He also appeared with Lillian Gish in 1934's Within the Gates and his last role before his death in The Flowers of the Forest with Burgess Meredith and Katharine Cornell.
[7] Devoted to the stage, Johnston only appeared in two films: a 1911 Shakespearean silent Richard III starring Frank Benson and the 1934 sound drama Midnight.