Watertown Town, MA has a population of 33,849 and is the 1,251st largest city in the United States. The population density is 8,478 per sq mi which is 1246% higher than the Massachusetts average and 9258% higher than the national average. The median age in Watertown Town is 38 which is approximately 3% lower than the Massachusetts average of 39. In Watertown Town, 51% of the population over 15 years of age are married, 73% speak English and 7% speak Spanish. 54% of Watertown Town residents were born in Massachusetts, 24% were born out of state, 2% were born outside of the United States and 20% were foreign born.