| South Portland to Cortona | 3,942.18 mi (6,344.33 km) |
| South Portland to Cosenza | 4,277.61 mi (6,884.15 km) |
| South Portland to Cossato | 3,699.97 mi (5,954.53 km) |
| South Portland to Costa Volpino | 3,773.19 mi (6,072.36 km) |
| South Portland to Creazzo | 3,841.50 mi (6,182.30 km) |
| South Portland to Crema | 3,771.12 mi (6,069.02 km) |
| South Portland to Cremona | 3,793.84 mi (6,105.59 km) |
| South Portland to Crevalcore | 3,855.55 mi (6,204.91 km) |
| South Portland to Crispiano | 4,268.87 mi (6,870.08 km) |
| South Portland to Crosia | 4,289.59 mi (6,903.43 km) |
| South Portland to Crotone | 4,324.16 mi (6,959.06 km) |
| South Portland to Cuneo | 3,712.35 mi (5,974.45 km) |
| South Portland to Cuorgne | 3,683.64 mi (5,928.25 km) |
| South Portland to Cusano Milanino | 3,743.78 mi (6,025.03 km) |
| South Portland to Cutro | 4,320.31 mi (6,952.87 km) |
