William John Hanna, KC (October 13, 1862 – March 20, 1919) was a lawyer and political figure in Ontario, Canada.
He attended Sarnia Collegiate Institute and, after graduating, taught at a primary school near his home for three years.
He then studied law at Osgoode Hall in Toronto, Ontario, was called to the bar in 1890 and set up practice in Sarnia.
[1] Near the end of 1918, the Hanna family had been shaken by the death in Italy of his son, William Neil, a Royal Air Force lieutenant.
[1] Hanna Avenue in Liberty Village, site of the Central Prison for which he closed, is named in his honour.