Chatham, LA has a population of 601 and is the 18,428th largest city in the United States. The population density is 608 per sq mi which is 586% higher than the Louisiana average and 571% higher than the national average. The median age in Chatham is 33 which is approximately 9% lower than the Louisiana average of 36. In Chatham, 54% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 88% of Chatham residents were born in Louisiana, 12% were born out of state, 0% were born outside of the United States and 0% were foreign born.