Thompson Beach, South Australia  Thompson Beach is a locality in the Australian state of South Australia located on the eastern coastline of Gulf St Vincent about north of the Adelaide city centre. Thompson Beach started as a sub-division in 1980 with boundaries being created in June 1997. Land use with the locality is principally residential with built development being of a ‘low density’. Thompson Beach is located within the federal Division of Grey, the state electoral district of Narungga, and the local government area of the Adelaide Plains Council.