Lake Wylie is a census-designated place (CDP) in York County, South Carolina, United States.

As a result of the community's proximity to the state line between North and South Carolina, it has been significantly affected by recent efforts to resurvey the state line using modern global positioning system technology.

[7] The process moved the state line approximately 150 feet (46 m) southward in the Lake Wylie area, resulting in several properties in the community now being located in South Point Township in North Carolina — including one property where the new state line falls between the owner's house and his back deck,[8] and a gas station and convenience store whose owner has noted that differences in gas prices and retail regulations between the two states will probably force him out of business.

As of the 2020 United States census, there were 13,655 people, 4,869 households, and 3,894 families residing in the CDP.

[11] Lake Wylie's population grew to around 12,000 during the 2010s as younger families were drawn there from all over the U.S. by low tax rates and the local schools.

As a result, local infrastructure such as the roads and the water supply system were stressed by the demand, with traffic congestion regularly occurring on local roads and frequent boil-water advisories.

York County has declared a moratorium on all new construction in order to better plan the area's development.