| Middleburg to Olympia Heights (Florida) | 313.76 mi (504.94 km) |
| Middleburg to Omaha (Nebraska) | 1,106.86 mi (1,781.32 km) |
| Middleburg to On Top of the World Designated Place (Florida) | 69.24 mi (111.43 km) |
| Middleburg to Onalaska (Wisconsin) | 1,083.70 mi (1,744.05 km) |
| Middleburg to Oneida (New York) | 963.62 mi (1,550.80 km) |
| Middleburg to Oneonta (New York) | 937.06 mi (1,508.05 km) |
| Middleburg to Ontario (California) | 2,098.58 mi (3,377.33 km) |
| Middleburg to Ontario (Oregon) | 2,140.29 mi (3,444.47 km) |
| Middleburg to Opa-locka (Florida) | 303.84 mi (488.98 km) |
| Middleburg to Opelika (Alabama) | 273.10 mi (439.51 km) |
| Middleburg to Opelousas (Louisiana) | 608.07 mi (978.60 km) |
| Middleburg to Orange (California) | 2,111.68 mi (3,398.41 km) |
| Middleburg to Orange (Texas) | 708.72 mi (1,140.57 km) |
| Middleburg to Orange City (Florida) | 85.43 mi (137.49 km) |
| Middleburg to Orangeburg (South Carolina) | 245.49 mi (395.07 km) |
