| South Portland to Cullman (Alabama) | 1,100.50 mi (1,771.09 km) |
| South Portland to Culpeper (Virginia) | 536.74 mi (863.80 km) |
| South Portland to Culver City (California) | 2,634.86 mi (4,240.40 km) |
| South Portland to Cumberland (Maryland) | 516.15 mi (830.66 km) |
| South Portland to Cupertino (California) | 2,710.52 mi (4,362.16 km) |
| South Portland to Cutler Bay (Florida) | 1,369.55 mi (2,204.08 km) |
| South Portland to Cutlerville (Michigan) | 775.20 mi (1,247.56 km) |
| South Portland to Cuyahoga Falls (Ohio) | 597.33 mi (961.30 km) |
| South Portland to Cypress (California) | 2,623.34 mi (4,221.87 km) |
| South Portland to Cypress Gardens (Florida) | 1,251.62 mi (2,014.29 km) |
| South Portland to Cypress Lake (Florida) | 1,347.98 mi (2,169.36 km) |
| South Portland to D'Iberville (Mississippi) | 1,365.32 mi (2,197.28 km) |
| South Portland to Dakota Ridge (Colorado) | 1,807.33 mi (2,908.61 km) |
| South Portland to Dale City (Virginia) | 503.03 mi (809.55 km) |
| South Portland to Dallas (Georgia) | 1,029.31 mi (1,656.52 km) |
