
Summit County
- State:
- Colorado
- County Seat:
- Breckenridge
Summit County's estimated 2025 population is 30,123 with a growth rate of -0.56% in the past year according to the most recent United States census data. Summit County is the 20th largest county in Colorado. The 2010 population was 28,075 and has seen a growth of 7.29% since that time.