| Key West to Oswego (Illinois) | 1,241.23 mi (1,997.56 km) |
| Key West to Oswego (New York) | 1,338.79 mi (2,154.58 km) |
| Key West to Otsego (Minnesota) | 1,575.89 mi (2,536.15 km) |
| Key West to Ottawa (Illinois) | 1,228.90 mi (1,977.72 km) |
| Key West to Ottawa (Kansas) | 1,250.19 mi (2,011.99 km) |
| Key West to Ottumwa (Iowa) | 1,291.67 mi (2,078.74 km) |
| Key West to Overland (Missouri) | 1,098.18 mi (1,767.36 km) |
| Key West to Overland Park (Kansas) | 1,244.10 mi (2,002.19 km) |
| Key West to Overlea (Maryland) | 1,067.51 mi (1,717.98 km) |
| Key West to Oviedo (Florida) | 285.19 mi (458.97 km) |
| Key West to Owasso (Oklahoma) | 1,162.45 mi (1,870.78 km) |
| Key West to Owatonna (Minnesota) | 1,495.65 mi (2,407.02 km) |
| Key West to Owensboro (Kentucky) | 964.20 mi (1,551.73 km) |
| Key West to Owings Mills (Maryland) | 1,066.16 mi (1,715.82 km) |
| Key West to Owosso (Michigan) | 1,280.76 mi (2,061.18 km) |
