Adelaide, the capital city of South Australia, is strategically located on the Adelaide Plains, bordered by the Gulf St Vincent to the west and the Mount Lofty Ranges to the east. This unique positioning provides the city with a rich variety of landscapes and a temperate climate, making it one of Australia’s most picturesque urban centers.

The metropolitan area stretches 20 km (12 mi) from the coast to the foothills and spans 90 km (56 mi) from Gawler in the north to Sellicks Beach in the south. The land area within the Adelaide Metropolitan Region covers 870 km² (340 sq mi), with a broader definition encompassing the Greater Adelaide statistical area, which measures 3,259.8 km² (1,258.6 sq mi). Situated at an average elevation of just 50 meters (160 feet) above sea level, the city’s landscape is predominantly flat with significant variations in its natural surroundings.

To the east, the Mount Lofty Ranges rise dramatically, with the highest peak, Mount Lofty, reaching an elevation of 727 meters (2,385 feet). These ranges are a defining feature of the city's geography and offer panoramic views of the surrounding region. The city itself lies at the intersection of fertile plains and rolling hills, providing residents with a unique blend of urban life and natural beauty.

Adelaide's environment was once largely covered by bushland, although urbanization has transformed much of its original landscape. Sandhills, swamps, and marshlands were once common, particularly along the coast, but these areas have been significantly altered due to coastal development. The loss of the sandhills has led to increased erosion along the coastline. However, the government has taken steps to address this, including projects to restore and vegetate dunes in beachside suburbs. Tennyson Dunes, located within the city, is the largest remaining tertiary dune system and serves as a refuge for many native species that once populated the coastline.

While much of Adelaide's original vegetation has been cleared for urban development, some areas have been preserved in national parks and reserves. Cleland National Park and Belair National Park are two key examples of such conservation efforts, offering both locals and tourists access to native flora and fauna.

In addition to its natural landscapes, Adelaide is home to several important creeks and rivers, with the Torrens and Onkaparinga catchments being the largest. These waterways contribute to the city’s water supply, with reservoirs like the Happy Valley Reservoir providing around 40% of the city's domestic water needs, and the larger Mount Bold Reservoir supplying another 10%.

Adelaide's diverse geography—from coastal sandhills and urban landscapes to mountain ranges and preserved bushland—shapes both the city's environment and its development, making it a unique place to live and visit.