| Clemson to Orbetello | 4,839.13 mi (7,787.83 km) |
| Clemson to Oria | 5,192.73 mi (8,356.90 km) |
| Clemson to Oristano | 4,804.54 mi (7,732.16 km) |
| Clemson to Orta Nova | 5,077.27 mi (8,171.08 km) |
| Clemson to Orte | 4,890.47 mi (7,870.46 km) |
| Clemson to Ortona | 4,982.93 mi (8,019.25 km) |
| Clemson to Orvieto | 4,869.45 mi (7,836.62 km) |
| Clemson to Orzinuovi | 4,685.91 mi (7,541.25 km) |
| Clemson to Osimo | 4,903.16 mi (7,890.87 km) |
| Clemson to Ospitaletto | 4,686.97 mi (7,542.95 km) |
| Clemson to Ostuni | 5,181.72 mi (8,339.17 km) |
| Clemson to Ottaviano | 5,040.07 mi (8,111.21 km) |
| Clemson to Ovada | 4,654.13 mi (7,490.10 km) |
| Clemson to Ozieri | 4,801.09 mi (7,726.60 km) |
| Clemson to Paceco | 5,055.12 mi (8,135.44 km) |
