| Mercer Island to Octeville | 4,845.59 mi (7,798.23 km) |
| Mercer Island to Oignies | 4,922.50 mi (7,922.00 km) |
| Mercer Island to Oissel | 4,935.66 mi (7,943.18 km) |
| Mercer Island to Olivet | 5,039.94 mi (8,111.01 km) |
| Mercer Island to Ollioules | 5,417.19 mi (8,718.13 km) |
| Mercer Island to Olonne-sur-Mer | 5,010.54 mi (8,063.69 km) |
| Mercer Island to Oloron-Sainte-Marie | 5,229.38 mi (8,415.87 km) |
| Mercer Island to Onet Village | 5,256.47 mi (8,459.46 km) |
| Mercer Island to Onnaing | 4,942.50 mi (7,954.19 km) |
| Mercer Island to Orange | 5,331.05 mi (8,579.49 km) |
| Mercer Island to Orchies | 4,928.59 mi (7,931.81 km) |
| Mercer Island to Orleans | 5,038.01 mi (8,107.89 km) |
| Mercer Island to Orly | 5,003.75 mi (8,052.76 km) |
| Mercer Island to Ormesson-sur-Marne | 5,005.26 mi (8,055.18 km) |
| Mercer Island to Orsay | 5,000.87 mi (8,048.12 km) |
