| Hertford to Oakley (California) | 5,306.96 mi (8,540.73 km) |
| Hertford to Oakton (Virginia) | 3,671.94 mi (5,909.41 km) |
| Hertford to Oakville (Missouri) | 4,206.70 mi (6,770.02 km) |
| Hertford to Oatfield (Oregon) | 4,902.69 mi (7,890.12 km) |
| Hertford to Ocala (Florida) | 4,336.96 mi (6,979.67 km) |
| Hertford to Ocean Acres (New Jersey) | 3,510.77 mi (5,650.04 km) |
| Hertford to Ocean City (New Jersey) | 3,545.00 mi (5,705.13 km) |
| Hertford to Ocean Pines (Maryland) | 3,607.02 mi (5,804.94 km) |
| Hertford to Ocean Pointe (Hawaii) | 7,212.08 mi (11,606.72 km) |
| Hertford to Ocean Springs (Mississippi) | 4,547.01 mi (7,317.71 km) |
| Hertford to Oceanside (California) | 5,446.15 mi (8,764.72 km) |
| Hertford to Oceanside (New York) | 3,445.44 mi (5,544.90 km) |
| Hertford to Ocoee (Florida) | 4,341.23 mi (6,986.54 km) |
| Hertford to Oconomowoc (Wisconsin) | 3,915.81 mi (6,301.89 km) |
| Hertford to Odenton (Maryland) | 3,639.25 mi (5,856.80 km) |
