| Hertford to Oswego (Illinois) | 3,976.11 mi (6,398.93 km) |
| Hertford to Oswego (New York) | 3,438.88 mi (5,534.34 km) |
| Hertford to Otsego (Minnesota) | 4,000.80 mi (6,438.66 km) |
| Hertford to Ottawa (Illinois) | 4,010.06 mi (6,453.57 km) |
| Hertford to Ottawa (Kansas) | 4,385.81 mi (7,058.28 km) |
| Hertford to Ottumwa (Iowa) | 4,160.74 mi (6,696.06 km) |
| Hertford to Overland (Missouri) | 4,196.44 mi (6,753.52 km) |
| Hertford to Overland Park (Kansas) | 4,349.99 mi (7,000.64 km) |
| Hertford to Overlea (Maryland) | 3,618.66 mi (5,823.67 km) |
| Hertford to Oviedo (Florida) | 4,322.87 mi (6,956.98 km) |
| Hertford to Owasso (Oklahoma) | 4,523.82 mi (7,280.39 km) |
| Hertford to Owatonna (Minnesota) | 4,042.71 mi (6,506.11 km) |
| Hertford to Owensboro (Kentucky) | 4,116.17 mi (6,624.33 km) |
| Hertford to Owings Mills (Maryland) | 3,627.63 mi (5,838.10 km) |
| Hertford to Owosso (Michigan) | 3,757.37 mi (6,046.90 km) |
