| Harpenden to Dixon (Illinois) | 4,000.54 mi (6,438.25 km) |
| Harpenden to Dobbs Ferry (New York) | 3,426.78 mi (5,514.87 km) |
| Harpenden to Doctor Phillips (Florida) | 4,334.34 mi (6,975.44 km) |
| Harpenden to Dodge City (Kansas) | 4,592.34 mi (7,390.66 km) |
| Harpenden to Dolton (Illinois) | 3,939.57 mi (6,340.13 km) |
| Harpenden to Donna (Texas) | 5,127.86 mi (8,252.49 km) |
| Harpenden to Dorado (Puerto Rico) | 4,199.32 mi (6,758.15 km) |
| Harpenden to Doral (Florida) | 4,419.68 mi (7,112.79 km) |
| Harpenden to Doraville (Georgia) | 4,178.21 mi (6,724.19 km) |
| Harpenden to Dothan (Alabama) | 4,356.60 mi (7,011.26 km) |
| Harpenden to Douglas (Arizona) | 5,276.91 mi (8,492.37 km) |
| Harpenden to Douglas (Georgia) | 4,238.42 mi (6,821.08 km) |
| Harpenden to Douglasville (Georgia) | 4,204.07 mi (6,765.80 km) |
| Harpenden to Dover (Delaware) | 3,575.61 mi (5,754.39 km) |
| Harpenden to Dover (New Hampshire) | 3,213.77 mi (5,172.06 km) |
