The City of Casey is a local government area in Victoria, Australia in the outer south-eastern suburbs of Melbourne. Casey is Victoria's most populous municipality, with a 2011 census population of 252,382. The municipality's population growth rate during both 1996–2001 and 2001–2006 was higher, in absolute terms, than other rapidly growing outer Melbourne municipalities. It has an area of 409.9 square kilometres (158.3 sq mi).
The City is named after Lord Casey, the 16th Governor-General of Australia, and was formed in 1994 by the merger of the City of Berwick with parts of Shire of Cranbourne (including Cranbourne itself), as well as the Churchill Park Drive estate within the City of Knox.
Casey spreads from the base of the Dandenong Ranges in the north to the shoreline of Western Port in the south. It features a wide variety of geographical features, due to its outer metropolitan location.
The north, in the foothills of the Dandenongs, is primarily made up of large blocks of land used for grazing, with some small vineyards in operation. An Urban Growth Boundary has been in place since 2005 to protect this area from future residential subdivision.