| McDonough to Oswego (Illinois) | 613.80 mi (987.81 km) |
| McDonough to Oswego (New York) | 805.32 mi (1,296.03 km) |
| McDonough to Otsego (Minnesota) | 959.51 mi (1,544.19 km) |
| McDonough to Ottawa (Illinois) | 603.90 mi (971.88 km) |
| McDonough to Ottawa (Kansas) | 715.33 mi (1,151.22 km) |
| McDonough to Ottumwa (Iowa) | 692.97 mi (1,115.23 km) |
| McDonough to Overland (Missouri) | 502.27 mi (808.33 km) |
| McDonough to Overland Park (Kansas) | 697.19 mi (1,122.03 km) |
| McDonough to Overlea (Maryland) | 589.26 mi (948.33 km) |
| McDonough to Oviedo (Florida) | 374.01 mi (601.91 km) |
| McDonough to Owasso (Oklahoma) | 690.30 mi (1,110.92 km) |
| McDonough to Owatonna (Minnesota) | 882.45 mi (1,420.17 km) |
| McDonough to Owensboro (Kentucky) | 341.68 mi (549.88 km) |
| McDonough to Owings Mills (Maryland) | 580.65 mi (934.47 km) |
| McDonough to Owosso (Michigan) | 660.24 mi (1,062.56 km) |
