Cayce is a city in the U.S. state of South Carolina, along the Congaree River. The population was 12,528 at the 2010 census and rose to 13,789 in the 2020 United States Census, and it is the third-most populated municipality in Lexington County. The city is primarily in Lexington County, with additional, predominantly rural land to the east in Richland County. Cayce is part of the Columbia Metropolitan Statistical Area and is within South Carolina's Midlands region.

As defined by the U.S. Office of Management and Budget, and used by the U.S. Census Bureau for statistical purposes only, the Columbia, SC Metropolitan Statistical Area, is an area consisting of six counties in central South Carolina, anchored by the city of Columbia. The current population has an estimation of 837,092. It is the second-largest metropolitan statistical area in the state of South Carolina, since the Anderson metropolitan statistical area was combined with Greenville's following the 2010 census.