Thomaston, CT has a population of 1,803 and is the 11,631st largest city in the United States. The population density is 1,766 per sq mi which is 173% higher than the Connecticut average and 1849% higher than the national average. The median age in Thomaston is 46 which is approximately 13% higher than the Connecticut average of 41. In Thomaston, 50% of the population over 15 years of age are married, 98% speak English and 0% speak Spanish. 88% of Thomaston residents were born in Connecticut, 11% were born out of state, 0% were born outside of the United States and 1% were foreign born.