Millbury, OH has a population of 1,229 and is the 13,888th largest city in the United States. The population density is 1,234 per sq mi which is 379% higher than the Ohio average and 1262% higher than the national average. The median age in Millbury is 42 which is approximately 8% higher than the Ohio average of 39. In Millbury, 66% of the population over 15 years of age are married, 96% speak English and 1% speak Spanish. 88% of Millbury residents were born in Ohio, 10% were born out of state, 0% were born outside of the United States and 2% were foreign born.