| Harpenden to Cockermouth | 232.53 mi (374.23 km) |
| Harpenden to Colchester | 53.82 mi (86.61 km) |
| Harpenden to Coleford | 96.73 mi (155.67 km) |
| Harpenden to Colne | 160.04 mi (257.56 km) |
| Harpenden to Colwyn Bay | 173.55 mi (279.30 km) |
| Harpenden to Congleton | 121.58 mi (195.66 km) |
| Harpenden to Conisbrough | 120.51 mi (193.94 km) |
| Harpenden to Connahs Quay | 149.29 mi (240.27 km) |
| Harpenden to Consett | 218.20 mi (351.16 km) |
| Harpenden to Conwy | 177.62 mi (285.85 km) |
| Harpenden to Cookstown | 328.60 mi (528.84 km) |
| Harpenden to Corby | 48.61 mi (78.23 km) |
| Harpenden to Corfe Mullen | 102.04 mi (164.21 km) |
| Harpenden to Corsham | 82.95 mi (133.49 km) |
| Harpenden to Coseley | 89.08 mi (143.36 km) |
