| Hertford to Odessa (Texas) | 4,997.90 mi (8,043.35 km) |
| Hertford to Ogden (Utah) | 4,826.17 mi (7,766.97 km) |
| Hertford to Oildale (California) | 5,374.40 mi (8,649.27 km) |
| Hertford to Ojus (Florida) | 4,416.08 mi (7,107.00 km) |
| Hertford to Okemos (Michigan) | 3,779.58 mi (6,082.64 km) |
| Hertford to Oklahoma City (Oklahoma) | 4,629.06 mi (7,449.74 km) |
| Hertford to Okmulgee (Oklahoma) | 4,564.85 mi (7,346.41 km) |
| Hertford to Olathe (Kansas) | 4,355.13 mi (7,008.90 km) |
| Hertford to Old Jamestown (Missouri) | 4,186.27 mi (6,737.15 km) |
| Hertford to Oldsmar (Florida) | 4,415.23 mi (7,105.62 km) |
| Hertford to Olean (New York) | 3,574.53 mi (5,752.64 km) |
| Hertford to Olive Branch (Mississippi) | 4,360.26 mi (7,017.16 km) |
| Hertford to Olivehurst (California) | 5,239.83 mi (8,432.68 km) |
| Hertford to Olney (Maryland) | 3,650.93 mi (5,875.61 km) |
| Hertford to Olympia (Washington) | 4,816.87 mi (7,752.01 km) |
