Lionel Herbert Clarke (July 20, 1859 – August 29, 1921) was a Guelph-born businessman and the 12th Lieutenant Governor of Ontario, Canada. In 1911, he was appointed the first chairman of the Toronto Harbour Commission The son of William Clarke and Clara Piggott Strange, he was educated in Port Hope. In 1891, Clarke married Anne Clara Gertrude Small. In 1893, Lionel partnered with "barley king" Wilmot Deloui Matthews as L. H. Clarke and Company, malt dealers, then in 1900 they established the of which Clarke became president in 1908.