 Clarke was a very prominent Victorian Freemason and was elected provincial grand master of the Irish Constitution in 1881 and then district grand master of both the Scottish and English Constitutions in 1884.In 1889 he became the very first Most Worshipful Grand Master of the United Grand Lodge of Victoria, an amalgamation of the three bodies that had operated at that time under their own constitutions.In 1885 he had largely financed the building of the Freemasons' Hall at 25 Collins Street.