| Pittsburgh to Octeville | 3,701.22 mi (5,956.54 km) |
| Pittsburgh to Oignies | 3,867.38 mi (6,223.94 km) |
| Pittsburgh to Oissel | 3,821.89 mi (6,150.74 km) |
| Pittsburgh to Olivet | 3,897.98 mi (6,273.20 km) |
| Pittsburgh to Ollioules | 4,218.45 mi (6,788.94 km) |
| Pittsburgh to Olonne-sur-Mer | 3,779.56 mi (6,082.61 km) |
| Pittsburgh to Oloron-Sainte-Marie | 3,930.29 mi (6,325.19 km) |
| Pittsburgh to Onet Village | 4,035.37 mi (6,494.30 km) |
| Pittsburgh to Onnaing | 3,893.92 mi (6,266.66 km) |
| Pittsburgh to Orange | 4,139.42 mi (6,661.76 km) |
| Pittsburgh to Orchies | 3,877.26 mi (6,239.84 km) |
| Pittsburgh to Orleans | 3,897.20 mi (6,271.93 km) |
| Pittsburgh to Orly | 3,892.64 mi (6,264.61 km) |
| Pittsburgh to Ormesson-sur-Marne | 3,897.42 mi (6,272.30 km) |
| Pittsburgh to Orsay | 3,885.49 mi (6,253.10 km) |
