Quincy, OH has a population of 579 and is the 18,654th largest city in the United States. The population density is 511 per sq mi which is 98% higher than the Ohio average and 464% higher than the national average. The median age in Quincy is 40 which is approximately 2% higher than the Ohio average of 39. In Quincy, 60% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 85% of Quincy residents were born in Ohio, 15% were born out of state, 0% were born outside of the United States and 0% were foreign born.