Parker, CO has a population of 48,442 and is the 851st largest city in the United States. The population density is 2,226 per sq mi which is 4371% higher than the Colorado average and 2357% higher than the national average. The median age in Parker is 35 which is approximately 4% lower than the Colorado average of 36. In Parker, 66% of the population over 15 years of age are married, 90% speak English and 4% speak Spanish. 39% of Parker residents were born in Colorado, 53% were born out of state, 2% were born outside of the United States and 6% were foreign born.