| Skien to Olympia Heights (Florida) | 4,702.11 mi (7,567.32 km) |
| Skien to Omaha (Nebraska) | 4,312.64 mi (6,940.53 km) |
| Skien to On Top of the World Designated Place (Florida) | 4,574.19 mi (7,361.44 km) |
| Skien to Onalaska (Wisconsin) | 4,022.67 mi (6,473.86 km) |
| Skien to Oneida (New York) | 3,581.63 mi (5,764.07 km) |
| Skien to Oneonta (New York) | 3,594.79 mi (5,785.26 km) |
| Skien to Ontario (California) | 5,321.53 mi (8,564.18 km) |
| Skien to Ontario (Oregon) | 4,684.19 mi (7,538.48 km) |
| Skien to Opa-locka (Florida) | 4,689.12 mi (7,546.40 km) |
| Skien to Opelika (Alabama) | 4,473.83 mi (7,199.94 km) |
| Skien to Opelousas (Louisiana) | 4,813.89 mi (7,747.21 km) |
| Skien to Orange (California) | 5,341.47 mi (8,596.27 km) |
| Skien to Orange (Texas) | 4,890.65 mi (7,870.74 km) |
| Skien to Orange City (Florida) | 4,550.19 mi (7,322.82 km) |
| Skien to Orangeburg (South Carolina) | 4,277.32 mi (6,883.68 km) |
