Quincy, CA has a population of 1,582 and is the 12,391st largest city in the United States. The population density is 375 per sq mi which is 61% higher than the California average and 313% higher than the national average. The median age in Quincy is 50 which is approximately 39% higher than the California average of 36. In Quincy, 50% of the population over 15 years of age are married, 89% speak English and 6% speak Spanish. 63% of Quincy residents were born in California, 35% were born out of state, 0% were born outside of the United States and 2% were foreign born.