Corio was proclaimed a District on 3 April 1861. It was proclaimed a Shire on 21 June 1864. It was redefined by part of Lara Riding being severed and annexed to Bacchus Marsh Shire on 15 March 1911. Part of Steiglitz Riding of Bannockburn Shire was severed and annexed to Corio Shire on 31 May 1916. Part of Moorpanyal Riding was severed and annexed to Geelong West Town as West Ward on 9 December 1926. Local Government Reform 1993-1995 The Shire was abolished on 18 May 1993 as part of a statewide program of local government reform enacted between 1993 and 1995. The reform process reduced the number of councils from 210 to 78. The City of Greater Geelong (VA 3149) has been appointed as the successor in law of the Shire of Corio and has assumed its rights, assets and liabilities.