Groton, VT has a population of 423 and is the 20,566th largest city in the United States. The population density is 206 per sq mi which is 217% higher than the Vermont average and 128% higher than the national average. The median age in Groton is 42 which is approximately 2% lower than the Vermont average of 43. In Groton, 65% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 46% of Groton residents were born in Vermont, 53% were born out of state, 1% were born outside of the United States and 0% were foreign born.