| National City to Orangevale (California) | 475.99 mi (766.03 km) |
| National City to Orchards (Washington) | 945.12 mi (1,521.03 km) |
| National City to Orcutt (California) | 244.17 mi (392.95 km) |
| National City to Oregon (Ohio) | 1,940.68 mi (3,123.23 km) |
| National City to Oregon (Wisconsin) | 1,660.45 mi (2,672.24 km) |
| National City to Oregon City (Oregon) | 923.61 mi (1,486.41 km) |
| National City to Orem (Utah) | 606.38 mi (975.88 km) |
| National City to Orinda (California) | 460.25 mi (740.70 km) |
| National City to Orland Park (Illinois) | 1,714.61 mi (2,759.40 km) |
| National City to Orlando (Florida) | 2,136.92 mi (3,439.05 km) |
| National City to Ormond Beach (Florida) | 2,134.81 mi (3,435.65 km) |
| National City to Oro Valley (Arizona) | 356.90 mi (574.38 km) |
| National City to Oroville (California) | 533.81 mi (859.08 km) |
| National City to Oshkosh (Wisconsin) | 1,721.98 mi (2,771.26 km) |
| National City to Oskaloosa (Iowa) | 1,469.11 mi (2,364.30 km) |
