Greenwich, CT has a population of 13,429 and is the 3,115th largest city in the United States. The population density is 3,266 per sq mi which is 404% higher than the Connecticut average and 3505% higher than the national average. The median age in Greenwich is 42 which is approximately 3% higher than the Connecticut average of 41. In Greenwich, 53% of the population over 15 years of age are married, 65% speak English and 13% speak Spanish. 26% of Greenwich residents were born in Connecticut, 42% were born out of state, 2% were born outside of the United States and 30% were foreign born.