Fairmount, CO has a population of 8,484 and is the 4,471st largest city in the United States. The population density is 1,404 per sq mi which is 2719% higher than the Colorado average and 1449% higher than the national average. The median age in Fairmount is 45 which is approximately 24% higher than the Colorado average of 36. In Fairmount, 67% of the population over 15 years of age are married, 95% speak English and 4% speak Spanish. 50% of Fairmount residents were born in Colorado, 46% were born out of state, 1% were born outside of the United States and 3% were foreign born.