Brookline, MA has a population of 59,180 and is the 664th largest city in the United States. The population density is 8,754 per sq mi which is 1290% higher than the Massachusetts average and 9563% higher than the national average. The median age in Brookline is 34 which is approximately 15% lower than the Massachusetts average of 39. In Brookline, 50% of the population over 15 years of age are married, 69% speak English and 4% speak Spanish. 35% of Brookline residents were born in Massachusetts, 37% were born out of state, 2% were born outside of the United States and 26% were foreign born.