| Foster City to Olympia Heights (Florida) | 2,574.28 mi (4,142.90 km) |
| Foster City to Omaha (Nebraska) | 1,416.98 mi (2,280.41 km) |
| Foster City to On Top of the World Designated Place (Florida) | 2,361.76 mi (3,800.88 km) |
| Foster City to Onalaska (Wisconsin) | 1,673.30 mi (2,692.92 km) |
| Foster City to Oneida (New York) | 2,452.67 mi (3,947.20 km) |
| Foster City to Oneonta (New York) | 2,488.46 mi (4,004.79 km) |
| Foster City to Ontario (California) | 356.56 mi (573.82 km) |
| Foster City to Ontario (Oregon) | 525.51 mi (845.73 km) |
| Foster City to Opa-locka (Florida) | 2,572.98 mi (4,140.81 km) |
| Foster City to Opelika (Alabama) | 2,098.68 mi (3,377.49 km) |
| Foster City to Opelousas (Louisiana) | 1,786.50 mi (2,875.09 km) |
| Foster City to Orange (California) | 359.62 mi (578.76 km) |
| Foster City to Orange (Texas) | 1,706.95 mi (2,747.07 km) |
| Foster City to Orange City (Florida) | 2,421.42 mi (3,896.89 km) |
| Foster City to Orangeburg (South Carolina) | 2,326.07 mi (3,743.44 km) |
