According to the United States Census Bureau, the city has a total area of 6.9 square miles (18 km2), all land.
The city is bordered by the Jordan River on the west, 500 East and 700 East on the east, 2100 South on the north, and 3900 South on the south. West Valley City lies to the west, Salt Lake City to the north and northeast, and Millcreek to the east and south. Because of its location next to the Jordan River and well away from the mountains, it is mostly flat, only ranging in elevation from about 4,330 feet (1,320 m) to 4,380 feet (1,340 m).
According to estimates from the U.S. Census Bureau, as of 2017, there were 24,956 people in South Salt Lake. The racial makeup of the county was 52.4% non-Hispanic White, 8.3% Black, 2.5% Native American, 11.4% Asian, 2.1% Pacific Islander, and 3.6% from two or more races. 21.0% of the population were Hispanic or Latino of any race