| Middletown to Olympia Heights (Florida) | 980.18 mi (1,577.44 km) |
| Middletown to Omaha (Nebraska) | 626.47 mi (1,008.21 km) |
| Middletown to On Top of the World Designated Place (Florida) | 728.07 mi (1,171.72 km) |
| Middletown to Onalaska (Wisconsin) | 464.87 mi (748.14 km) |
| Middletown to Oneida (New York) | 514.54 mi (828.07 km) |
| Middletown to Oneonta (New York) | 525.83 mi (846.24 km) |
| Middletown to Ontario (California) | 1,866.98 mi (3,004.61 km) |
| Middletown to Ontario (Oregon) | 1,697.87 mi (2,732.46 km) |
| Middletown to Opa-locka (Florida) | 969.52 mi (1,560.29 km) |
| Middletown to Opelika (Alabama) | 476.09 mi (766.20 km) |
| Middletown to Opelousas (Louisiana) | 757.88 mi (1,219.69 km) |
| Middletown to Orange (California) | 1,884.46 mi (3,032.74 km) |
| Middletown to Orange (Texas) | 838.06 mi (1,348.73 km) |
| Middletown to Orange City (Florida) | 750.95 mi (1,208.53 km) |
| Middletown to Orangeburg (South Carolina) | 458.40 mi (737.72 km) |
