Louisville
- County:
- Boulder County
- County Seat:
- No
- Area (mi²):
- 7.971
- State:
- Colorado
Louisville is a city located in Boulder County, Colorado. Louisville has a 2026 population of 20,811. Louisville is currently growing at a rate of 1.35% annually but its population has decreased by -1.86% since the most recent census, which recorded a population of 21,205 in 2020.