| Willimantic to Odenton (Maryland) | 298.57 mi (480.51 km) |
| Willimantic to Odessa (Texas) | 1,788.78 mi (2,878.76 km) |
| Willimantic to Ogden (Utah) | 2,039.90 mi (3,282.91 km) |
| Willimantic to Oildale (California) | 2,534.44 mi (4,078.78 km) |
| Willimantic to Ojus (Florida) | 1,179.31 mi (1,897.92 km) |
| Willimantic to Okemos (Michigan) | 627.61 mi (1,010.05 km) |
| Willimantic to Oklahoma City (Oklahoma) | 1,426.96 mi (2,296.47 km) |
| Willimantic to Okmulgee (Oklahoma) | 1,346.08 mi (2,166.31 km) |
| Willimantic to Olathe (Kansas) | 1,203.75 mi (1,937.25 km) |
| Willimantic to Old Jamestown (Missouri) | 971.28 mi (1,563.12 km) |
| Willimantic to Oldsmar (Florida) | 1,112.91 mi (1,791.06 km) |
| Willimantic to Olean (New York) | 320.83 mi (516.33 km) |
| Willimantic to Olive Branch (Mississippi) | 1,060.89 mi (1,707.34 km) |
| Willimantic to Olivehurst (California) | 2,567.15 mi (4,131.43 km) |
| Willimantic to Olney (Maryland) | 311.17 mi (500.78 km) |
