Casey City was formed in 1994 by the union of most of Berwick City, the western half of Cranbourne Shire and part of Sherbrooke Shire. Its area is 395 square km and it is headquartered at the former Berwick City offices at Fountain Gate, Narre Warren. It is named after Baron Casey of Berwick, Victoria and the City of Westminster (1890-1976) politician and Australian governor-general. Casey lived at Edrington, Berwick, from the 1940s until his death.
Casey City's boundaries are: