| Richardson to Orbetello | 5,515.08 mi (8,875.66 km) |
| Richardson to Oria | 5,859.67 mi (9,430.22 km) |
| Richardson to Oristano | 5,504.70 mi (8,858.96 km) |
| Richardson to Orta Nova | 5,745.65 mi (9,246.72 km) |
| Richardson to Orte | 5,562.53 mi (8,952.03 km) |
| Richardson to Ortona | 5,649.05 mi (9,091.27 km) |
| Richardson to Orvieto | 5,540.66 mi (8,916.83 km) |
| Richardson to Orzinuovi | 5,345.19 mi (8,602.25 km) |
| Richardson to Osimo | 5,564.65 mi (8,955.44 km) |
| Richardson to Ospitaletto | 5,344.68 mi (8,601.44 km) |
| Richardson to Ostuni | 5,847.33 mi (9,410.36 km) |
| Richardson to Ottaviano | 5,715.80 mi (9,198.69 km) |
| Richardson to Ovada | 5,322.76 mi (8,566.16 km) |
| Richardson to Ozieri | 5,495.82 mi (8,844.66 km) |
| Richardson to Paceco | 5,754.86 mi (9,261.55 km) |
