| Holbrook to Orbetello | 4,161.37 mi (6,697.08 km) |
| Holbrook to Oria | 4,514.49 mi (7,265.37 km) |
| Holbrook to Oristano | 4,130.23 mi (6,646.96 km) |
| Holbrook to Orta Nova | 4,399.07 mi (7,079.62 km) |
| Holbrook to Orte | 4,212.44 mi (6,779.26 km) |
| Holbrook to Ortona | 4,304.57 mi (6,927.53 km) |
| Holbrook to Orvieto | 4,191.34 mi (6,745.31 km) |
| Holbrook to Orzinuovi | 4,007.26 mi (6,449.06 km) |
| Holbrook to Osimo | 4,224.60 mi (6,798.83 km) |
| Holbrook to Ospitaletto | 4,008.30 mi (6,450.73 km) |
| Holbrook to Ostuni | 4,503.40 mi (7,247.52 km) |
| Holbrook to Ottaviano | 4,362.40 mi (7,020.60 km) |
| Holbrook to Ovada | 3,975.79 mi (6,398.41 km) |
| Holbrook to Ozieri | 4,125.74 mi (6,639.73 km) |
| Holbrook to Paceco | 4,380.95 mi (7,050.45 km) |
