Clayton, IN has a population of 976 and is the 15,314th largest city in the United States. The population density is 1,280 per sq mi which is 613% higher than the Indiana average and 1313% higher than the national average. The median age in Clayton is 38 which is approximately equal to the Indiana average of 37. In Clayton, 68% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 81% of Clayton residents were born in Indiana, 18% were born out of state, 0% were born outside of the United States and 0% were foreign born.