Lexington, SC has a population of 20,315 and is the 2,142nd largest city in the United States. The population density is 2,045 per sq mi which is 1286% higher than the South Carolina average and 2157% higher than the national average. The median age in Lexington is 37 which is approximately 5% lower than the South Carolina average of 39. In Lexington, 59% of the population over 15 years of age are married, 91% speak English and 3% speak Spanish. 53% of Lexington residents were born in South Carolina, 39% were born out of state, 1% were born outside of the United States and 7% were foreign born.