Portland, CT has a population of 5,607 and is the 6,004th largest city in the United States. The population density is 988 per sq mi which is 53% higher than the Connecticut average and 991% higher than the national average. The median age in Portland is 48 which is approximately 18% higher than the Connecticut average of 41. In Portland, 57% of the population over 15 years of age are married, 94% speak English and 3% speak Spanish. 74% of Portland residents were born in Connecticut, 20% were born out of state, 2% were born outside of the United States and 4% were foreign born.