| Portsmouth to Cortona | 804.00 mi (1,293.91 km) |
| Portsmouth to Cosenza | 1,155.73 mi (1,859.96 km) |
| Portsmouth to Cossato | 558.51 mi (898.83 km) |
| Portsmouth to Costa Volpino | 617.31 mi (993.47 km) |
| Portsmouth to Creazzo | 682.91 mi (1,099.04 km) |
| Portsmouth to Crema | 622.15 mi (1,001.25 km) |
| Portsmouth to Cremona | 645.58 mi (1,038.96 km) |
| Portsmouth to Crevalcore | 705.66 mi (1,135.66 km) |
| Portsmouth to Crispiano | 1,125.49 mi (1,811.30 km) |
| Portsmouth to Crosia | 1,160.19 mi (1,867.15 km) |
| Portsmouth to Crotone | 1,197.56 mi (1,927.29 km) |
| Portsmouth to Cuneo | 598.27 mi (962.83 km) |
| Portsmouth to Cuorgne | 549.39 mi (884.17 km) |
| Portsmouth to Cusano Milanino | 595.57 mi (958.47 km) |
| Portsmouth to Cutro | 1,195.42 mi (1,923.84 km) |
