| National City to Oswego (Illinois) | 1,691.68 mi (2,722.49 km) |
| National City to Oswego (New York) | 2,304.97 mi (3,709.49 km) |
| National City to Otsego (Minnesota) | 1,523.44 mi (2,451.75 km) |
| National City to Ottawa (Illinois) | 1,662.20 mi (2,675.04 km) |
| National City to Ottawa (Kansas) | 1,289.17 mi (2,074.72 km) |
| National City to Ottumwa (Iowa) | 1,475.17 mi (2,374.05 km) |
| National City to Overland (Missouri) | 1,550.71 mi (2,495.62 km) |
| National City to Overland Park (Kansas) | 1,323.68 mi (2,130.26 km) |
| National City to Overlea (Maryland) | 2,294.82 mi (3,693.15 km) |
| National City to Oviedo (Florida) | 2,142.05 mi (3,447.29 km) |
| National City to Owasso (Oklahoma) | 1,234.23 mi (1,986.31 km) |
| National City to Owatonna (Minnesota) | 1,506.32 mi (2,424.19 km) |
| National City to Owensboro (Kentucky) | 1,720.89 mi (2,769.50 km) |
| National City to Owings Mills (Maryland) | 2,280.14 mi (3,669.53 km) |
| National City to Owosso (Michigan) | 1,917.99 mi (3,086.71 km) |
