The City of Rockdale was a local government area (LGA) in the southern suburbs of Sydney, New South Wales, Australia. It was situated approximately 10 kilometres south of the Sydney central business district and encompassed a number of suburbs along the western shore of Botany Bay.
The City of Rockdale was established on 12 December 1887 as the Municipality of Rockdale. Over its history, it underwent various boundary adjustments and was proclaimed a city on 16 August 1990. The council was responsible for local services, infrastructure, planning, and community facilities for its residents. Its administrative centre was located in Rockdale, from which it derived its name.
In May 2016, a major reform of local government in New South Wales saw the amalgamation of the City of Rockdale with the City of Botany Bay to form the new Bayside Council. This merger effectively dissolved the City of Rockdale as a distinct local government entity, though the geographic area and its former suburbs retain the historical significance and community identity associated with the former council.
The former City of Rockdale area includes suburbs such as Rockdale, Arncliffe, Banksia, Bexley, Brighton-le-Sands, Dolls Point, Kogarah, Kyeemagh, Ramsgate, Sandringham, Sans Souci, and Wolli Creek, among others. Its coastal location and proximity to Sydney Airport were significant characteristics influencing its development and planning throughout its existence.