South Windham, CT has a population of 1,330 and is the 13,415th largest city in the United States. The population density is 428 per sq mi which is 34% lower than the Connecticut average and 372% higher than the national average. The median age in South Windham is 34 which is approximately 15% lower than the Connecticut average of 41. In South Windham, 51% of the population over 15 years of age are married, 74% speak English and 19% speak Spanish. 68% of South Windham residents were born in Connecticut, 13% were born out of state, 12% were born outside of the United States and 7% were foreign born.