Summerlin South, also seen on maps as South Summerlin, is a census-designated place in Clark County, Nevada, United States, on the western edge of the Las Vegas Valley and adjacent to the Red Rock Canyon National Conservation Area. It is so named because it is a southward extension of the master-planned community of Summerlin. Nearly all of Summerlin South is in ZIP code 89135. The population was 24,085 at the 2010 Census.