| Castlebar to Orthez | 814.15 mi (1,310.25 km) |
| Castlebar to Orvault | 565.67 mi (910.35 km) |
| Castlebar to Osny | 589.91 mi (949.37 km) |
| Castlebar to Ostwald | 819.95 mi (1,319.59 km) |
| Castlebar to Ouistreham | 500.29 mi (805.14 km) |
| Castlebar to Oullins | 841.51 mi (1,354.28 km) |
| Castlebar to Outreau | 508.77 mi (818.79 km) |
| Castlebar to Oyonnax | 843.35 mi (1,357.24 km) |
| Castlebar to Ozoir-la-Ferriere | 623.94 mi (1,004.14 km) |
| Castlebar to Pace | 512.12 mi (824.17 km) |
| Castlebar to Palaiseau | 611.42 mi (983.98 km) |
| Castlebar to Pamiers | 892.60 mi (1,436.49 km) |
| Castlebar to Panazol | 726.85 mi (1,169.75 km) |
| Castlebar to Pantin | 608.94 mi (980.00 km) |
| Castlebar to Paray-le-Monial | 781.90 mi (1,258.35 km) |
