| Harmanli to Olympia Heights (Florida) | 5,811.37 mi (9,352.49 km) |
| Harmanli to Omaha (Nebraska) | 5,643.20 mi (9,081.85 km) |
| Harmanli to On Top of the World Designated Place (Florida) | 5,733.46 mi (9,227.11 km) |
| Harmanli to Onalaska (Wisconsin) | 5,344.43 mi (8,601.03 km) |
| Harmanli to Oneida (New York) | 4,813.43 mi (7,746.46 km) |
| Harmanli to Oneonta (New York) | 4,816.92 mi (7,752.08 km) |
| Harmanli to Ontario (California) | 6,700.63 mi (10,783.62 km) |
| Harmanli to Ontario (Oregon) | 6,068.16 mi (9,765.77 km) |
| Harmanli to Opa-locka (Florida) | 5,799.18 mi (9,332.88 km) |
| Harmanli to Opelika (Alabama) | 5,688.81 mi (9,155.26 km) |
| Harmanli to Opelousas (Louisiana) | 6,064.92 mi (9,760.55 km) |
| Harmanli to Orange (California) | 6,720.70 mi (10,815.92 km) |
| Harmanli to Orange (Texas) | 6,151.31 mi (9,899.57 km) |
| Harmanli to Orange City (Florida) | 5,698.62 mi (9,171.04 km) |
| Harmanli to Orangeburg (South Carolina) | 5,462.45 mi (8,790.97 km) |
