| Castro Valley to Octeville | 5,394.97 mi (8,682.36 km) |
| Castro Valley to Oignies | 5,491.75 mi (8,838.12 km) |
| Castro Valley to Oissel | 5,493.44 mi (8,840.84 km) |
| Castro Valley to Olivet | 5,594.08 mi (9,002.80 km) |
| Castro Valley to Ollioules | 5,966.69 mi (9,602.46 km) |
| Castro Valley to Olonne-sur-Mer | 5,544.33 mi (8,922.74 km) |
| Castro Valley to Oloron-Sainte-Marie | 5,751.46 mi (9,256.08 km) |
| Castro Valley to Onet Village | 5,797.69 mi (9,330.48 km) |
| Castro Valley to Onnaing | 5,513.45 mi (8,873.03 km) |
| Castro Valley to Orange | 5,880.42 mi (9,463.62 km) |
| Castro Valley to Orchies | 5,498.71 mi (8,849.32 km) |
| Castro Valley to Orleans | 5,592.34 mi (9,000.01 km) |
| Castro Valley to Orly | 5,563.55 mi (8,953.67 km) |
| Castro Valley to Ormesson-sur-Marne | 5,565.75 mi (8,957.22 km) |
| Castro Valley to Orsay | 5,559.72 mi (8,947.51 km) |
