| Willimantic to Oskaloosa (Iowa) | 1,055.01 mi (1,697.87 km) |
| Willimantic to Oswego (Illinois) | 830.67 mi (1,336.84 km) |
| Willimantic to Oswego (New York) | 248.89 mi (400.56 km) |
| Willimantic to Otsego (Minnesota) | 1,097.26 mi (1,765.87 km) |
| Willimantic to Ottawa (Illinois) | 858.32 mi (1,381.34 km) |
| Willimantic to Ottawa (Kansas) | 1,232.34 mi (1,983.26 km) |
| Willimantic to Ottumwa (Iowa) | 1,046.50 mi (1,684.19 km) |
| Willimantic to Overland (Missouri) | 978.61 mi (1,574.93 km) |
| Willimantic to Overland Park (Kansas) | 1,196.82 mi (1,926.10 km) |
| Willimantic to Overlea (Maryland) | 278.42 mi (448.07 km) |
| Willimantic to Oviedo (Florida) | 1,033.48 mi (1,663.22 km) |
| Willimantic to Owasso (Oklahoma) | 1,317.75 mi (2,120.71 km) |
| Willimantic to Owatonna (Minnesota) | 1,073.37 mi (1,727.43 km) |
| Willimantic to Owensboro (Kentucky) | 836.57 mi (1,346.32 km) |
| Willimantic to Owings Mills (Maryland) | 288.32 mi (464.00 km) |
