Andover, KS has a population of 12,477 and is the 3,310th largest city in the United States. The population density is 1,246 per sq mi which is 3452% higher than the Kansas average and 1275% higher than the national average. The median age in Andover is 34 which is approximately 6% lower than the Kansas average of 36. In Andover, 64% of the population over 15 years of age are married, 96% speak English and 2% speak Spanish. 59% of Andover residents were born in Kansas, 37% were born out of state, 1% were born outside of the United States and 2% were foreign born.