| Greenock to Olivares | 1,282.14 mi (2,063.41 km) |
| Greenock to Olivenza | 1,197.68 mi (1,927.47 km) |
| Greenock to Olot | 1,005.02 mi (1,617.42 km) |
| Greenock to Onate | 898.52 mi (1,446.03 km) |
| Greenock to Onda | 1,123.50 mi (1,808.09 km) |
| Greenock to Onteniente | 1,198.75 mi (1,929.21 km) |
| Greenock to Orihuela | 1,246.87 mi (2,006.65 km) |
| Greenock to Osuna | 1,293.29 mi (2,081.35 km) |
| Greenock to Ourense | 950.73 mi (1,530.05 km) |
| Greenock to Oviedo | 871.20 mi (1,402.06 km) |
| Greenock to Paiporta | 1,158.76 mi (1,864.85 km) |
| Greenock to Pajara | 1,962.01 mi (3,157.54 km) |
| Greenock to Palafolls | 1,042.81 mi (1,678.24 km) |
| Greenock to Palafrugell | 1,032.57 mi (1,661.76 km) |
| Greenock to Palamos | 1,036.77 mi (1,668.52 km) |
