| Fort Collins to Opole | 5,256.83 mi (8,460.05 km) |
| Fort Collins to Orzesze | 5,307.35 mi (8,541.35 km) |
| Fort Collins to Osowa | 5,076.16 mi (8,169.29 km) |
| Fort Collins to Ostroda | 5,153.82 mi (8,294.27 km) |
| Fort Collins to Ostroleka | 5,229.56 mi (8,416.17 km) |
| Fort Collins to Ostrow Mazowiecka | 5,252.62 mi (8,453.28 km) |
| Fort Collins to Ostrow Wielkopolski | 5,202.38 mi (8,372.42 km) |
| Fort Collins to Ostrowiec Swietokrzyski | 5,339.84 mi (8,593.64 km) |
| Fort Collins to Ostrzeszow | 5,217.78 mi (8,397.21 km) |
| Fort Collins to Oswiecim | 5,326.75 mi (8,572.58 km) |
| Fort Collins to Otwock | 5,272.63 mi (8,485.47 km) |
| Fort Collins to Ozarow Mazowiecki | 5,254.77 mi (8,456.73 km) |
| Fort Collins to Ozimek | 5,264.53 mi (8,472.44 km) |
| Fort Collins to Ozorkow | 5,226.75 mi (8,411.64 km) |
| Fort Collins to Pabianice | 5,246.20 mi (8,442.95 km) |
