| Irmo to Nuth | 4,318.06 mi (6,949.25 km) |
| Irmo to Oegstgeest | 4,230.50 mi (6,808.34 km) |
| Irmo to Oirschot | 4,280.12 mi (6,888.18 km) |
| Irmo to Oisterwijk | 4,274.08 mi (6,878.47 km) |
| Irmo to Oldebroek | 4,281.07 mi (6,889.71 km) |
| Irmo to Oldenzaal | 4,325.07 mi (6,960.52 km) |
| Irmo to Ommen | 4,299.79 mi (6,919.85 km) |
| Irmo to Oosterend | 4,274.28 mi (6,878.78 km) |
| Irmo to Oosterhout | 4,258.84 mi (6,853.94 km) |
| Irmo to Oosterwolde | 4,283.37 mi (6,893.41 km) |
| Irmo to Oostzaan | 4,241.25 mi (6,825.64 km) |
| Irmo to Opmeer | 4,237.67 mi (6,819.87 km) |
| Irmo to Oss | 4,282.36 mi (6,891.79 km) |
| Irmo to Oud-Beijerland | 4,236.37 mi (6,817.77 km) |
| Irmo to Oudenbosch | 4,246.70 mi (6,834.40 km) |
