| London Colney to Oswego (Illinois) | 3,969.96 mi (6,389.03 km) |
| London Colney to Oswego (New York) | 3,431.94 mi (5,523.17 km) |
| London Colney to Otsego (Minnesota) | 3,995.62 mi (6,430.33 km) |
| London Colney to Ottawa (Illinois) | 4,003.91 mi (6,443.67 km) |
| London Colney to Ottawa (Kansas) | 4,379.93 mi (7,048.81 km) |
| London Colney to Ottumwa (Iowa) | 4,154.88 mi (6,686.63 km) |
| London Colney to Overland (Missouri) | 4,190.10 mi (6,743.31 km) |
| London Colney to Overland Park (Kansas) | 4,344.09 mi (6,991.14 km) |
| London Colney to Overlea (Maryland) | 3,611.16 mi (5,811.60 km) |
| London Colney to Oviedo (Florida) | 4,314.60 mi (6,943.68 km) |
| London Colney to Owasso (Oklahoma) | 4,517.72 mi (7,270.58 km) |
| London Colney to Owatonna (Minnesota) | 4,037.33 mi (6,497.46 km) |
| London Colney to Owensboro (Kentucky) | 4,109.40 mi (6,613.44 km) |
| London Colney to Owings Mills (Maryland) | 3,620.15 mi (5,826.07 km) |
| London Colney to Owosso (Michigan) | 3,751.02 mi (6,036.68 km) |
