| Sumter to Orbetello | 4,762.21 mi (7,664.03 km) |
| Sumter to Oria | 5,117.55 mi (8,235.89 km) |
| Sumter to Oristano | 4,720.33 mi (7,596.64 km) |
| Sumter to Orta Nova | 5,001.96 mi (8,049.88 km) |
| Sumter to Orte | 4,814.56 mi (7,748.29 km) |
| Sumter to Ortona | 4,908.50 mi (7,899.47 km) |
| Sumter to Orvieto | 4,793.84 mi (7,714.94 km) |
| Sumter to Orzinuovi | 4,614.25 mi (7,425.92 km) |
| Sumter to Osimo | 4,830.27 mi (7,773.57 km) |
| Sumter to Ospitaletto | 4,615.76 mi (7,428.34 km) |
| Sumter to Ostuni | 5,106.94 mi (8,218.82 km) |
| Sumter to Ottaviano | 4,962.71 mi (7,986.71 km) |
| Sumter to Ovada | 4,579.84 mi (7,370.54 km) |
| Sumter to Ozieri | 4,718.58 mi (7,593.82 km) |
| Sumter to Paceco | 4,970.50 mi (7,999.25 km) |
