Jamestown, KS has a population of 383 and is the 21,117th largest city in the United States. The population density is 1,307 per sq mi which is 3626% higher than the Kansas average and 1343% higher than the national average. The median age in Jamestown is 32 which is approximately 11% lower than the Kansas average of 36. In Jamestown, 51% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 81% of Jamestown residents were born in Kansas, 18% were born out of state, 0% were born outside of the United States and 0% were foreign born.