| Fort Collins to Octeville | 4,671.00 mi (7,517.25 km) |
| Fort Collins to Oignies | 4,796.67 mi (7,719.49 km) |
| Fort Collins to Oissel | 4,780.05 mi (7,692.75 km) |
| Fort Collins to Olivet | 4,873.17 mi (7,842.60 km) |
| Fort Collins to Ollioules | 5,232.01 mi (8,420.10 km) |
| Fort Collins to Olonne-sur-Mer | 4,795.89 mi (7,718.24 km) |
| Fort Collins to Oloron-Sainte-Marie | 4,984.59 mi (8,021.92 km) |
| Fort Collins to Onet Village | 5,054.58 mi (8,134.56 km) |
| Fort Collins to Onnaing | 4,820.73 mi (7,758.22 km) |
| Fort Collins to Orange | 5,147.14 mi (8,283.52 km) |
| Fort Collins to Orchies | 4,804.92 mi (7,732.77 km) |
| Fort Collins to Orleans | 4,871.77 mi (7,840.35 km) |
| Fort Collins to Orly | 4,851.85 mi (7,808.29 km) |
| Fort Collins to Ormesson-sur-Marne | 4,855.10 mi (7,813.53 km) |
| Fort Collins to Orsay | 4,846.65 mi (7,799.93 km) |
