Waterfall Gully is an eastern suburb of the South Australian capital city of Adelaide. It is located in the foothills of the Mount Lofty Ranges around 5 km (3.1 mi) east-south-east of the Adelaide city centre. For the most part, the suburb encompasses one long gully with First Creek at its centre and Waterfall Gully Road running adjacent to the creek. At the southern end of the gully is First Falls, the waterfall for which the suburb was named. Part of the City of Burnside, Waterfall Gully is bounded to the north by the suburb of Burnside, from the north-east to south-east by Cleland National Park, to the south by Crafers West, and to the west by Leawood Gardens and Mount Osmond.

Adelaide city centre is the inner city locality of Greater Adelaide, the capital city of South Australia. It is known by locals simply as "the City" or "Town" to distinguish it from Greater Adelaide and from the City of Adelaide local government area. The population was 15,115 in the 2016 census.