| Middlesex to Orangevale (California) | 2,460.16 mi (3,959.25 km) |
| Middlesex to Orchards (Washington) | 2,410.62 mi (3,879.52 km) |
| Middlesex to Orcutt (California) | 2,511.77 mi (4,042.30 km) |
| Middlesex to Oregon (Ohio) | 470.61 mi (757.38 km) |
| Middlesex to Oregon (Wisconsin) | 783.33 mi (1,260.65 km) |
| Middlesex to Oregon City (Oregon) | 2,417.49 mi (3,890.58 km) |
| Middlesex to Orem (Utah) | 1,941.53 mi (3,124.58 km) |
| Middlesex to Orinda (California) | 2,527.39 mi (4,067.44 km) |
| Middlesex to Orland Park (Illinois) | 698.68 mi (1,124.42 km) |
| Middlesex to Orlando (Florida) | 921.20 mi (1,482.53 km) |
| Middlesex to Ormond Beach (Florida) | 863.47 mi (1,389.62 km) |
| Middlesex to Oro Valley (Arizona) | 2,086.48 mi (3,357.86 km) |
| Middlesex to Oroville (California) | 2,460.56 mi (3,959.88 km) |
| Middlesex to Oshkosh (Wisconsin) | 755.91 mi (1,216.51 km) |
| Middlesex to Oskaloosa (Iowa) | 946.41 mi (1,523.10 km) |
