Platteville, CO has a population of 2,628 and is the 9,534th largest city in the United States. The population density is 906 per sq mi which is 1720% higher than the Colorado average and 900% higher than the national average. The median age in Platteville is 33 which is approximately 10% lower than the Colorado average of 36. In Platteville, 56% of the population over 15 years of age are married, 78% speak English and 22% speak Spanish. 57% of Platteville residents were born in Colorado, 34% were born out of state, 0% were born outside of the United States and 9% were foreign born.