Originally the settlement was called White Plains, but the city was incorporated on October 16, 1874, and the name was changed. It was decided that "Kings Mountain" would be a more appropriate name since the community was close to the site of the historic 1780 Battle of Kings Mountain in York County, South Carolina, a turning point in the American Revolutionary War.
The Battle of Kings Mountain was proclaimed as "the turning point of the American Revolution" by Thomas Jefferson. Liberty Mountain, a play performed at the local theater, recounts the events of the battle. The downtown area is home to the museum, police station, and the Mauney Memorial Library.
The Central School Historic District, King Street Overhead Bridge, Margrace Mill Village Historic District, Jacob S. Mauney Memorial Library and Teacher's Home, Southern Railway Company Overhead Bridge, and West End Historic District are listed on the National Register of Historic Places.
Kings Mountain lies 30 miles (48 km) west of Charlotte along Interstate 85. Gaffney, South Carolina, is 21 miles (34 km) to the southwest along I-85.
According to the United States Census Bureau, the city has a total area of 12.6 square miles (32.6 km), of which 12.3 square miles (31.9 km) is land and 0.23 square miles (0.6 km), or 1.98%, is covered with water.
Kings Pinnacle is a small mountain located at the southeastern point of the city. Standing at 1,705 feet, it is the highest point in the Kings Mountain Belt of monadnock formations. It is one of the two mountains in Crowders Mountain State Park, where cleared trails lead to the pinnacle.
As of the 2020 United States census, there were 11,142 people, 4,151 households, and 2,536 families residing in the city.
As of the census of 2010, there were 10,296 people, 4,597 households, and 2,674 families residing in the city. The population density was 1,187.1 inhabitants per square mile (458.3/km). There were 4,064 housing units at an average density of 497.7 units per square mile (192.2 units/km). The racial makeup of the city was 74.85% White, 21.55% black, 0.15% Native American, 1.81% Asian, 0.02% Pacific Islander, 0.63% from other races, and 0.99% from two or more races. Hispanic or Latino of any race were 1.43% of the population.
There were 3,821 households, out of which 30.7% had children under the age of 18 living with them, 49.4% were married couples living together, 17.2% had a female householder with no husband present, and 30.0% were non-families. Of all households, 26.8% were made up of individuals, and 12.6% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 2.98.
In the city, the population was spread out, with 25.3% under the age of 18, 7.4% from 18 to 24, 27.3% from 25 to 44, 22.4% from 45 to 64, and 17.6% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 85.9 males. For every 100 females age 18 and over, there were 80.4 males.
The median income for a household in the city was $31,415, and the median income for a family was $39,137. Males had a median income of $32,444 versus $22,201 for females. The per capita income for the city was $15,920. About 13.4% of families and 19.2% of the population were below the poverty line, including 29.2% of those under age 18 and 20.7% of those age 65 or over.
