| Pencoed to Oswego (Illinois) | 3,853.59 mi (6,201.75 km) |
| Pencoed to Oswego (New York) | 3,309.20 mi (5,325.64 km) |
| Pencoed to Otsego (Minnesota) | 3,888.05 mi (6,257.21 km) |
| Pencoed to Ottawa (Illinois) | 3,887.54 mi (6,256.40 km) |
| Pencoed to Ottawa (Kansas) | 4,265.80 mi (6,865.14 km) |
| Pencoed to Ottumwa (Iowa) | 4,041.03 mi (6,503.41 km) |
| Pencoed to Overland (Missouri) | 4,072.05 mi (6,553.33 km) |
| Pencoed to Overland Park (Kansas) | 4,229.78 mi (6,807.17 km) |
| Pencoed to Overlea (Maryland) | 3,484.15 mi (5,607.19 km) |
| Pencoed to Oviedo (Florida) | 4,182.45 mi (6,731.01 km) |
| Pencoed to Owasso (Oklahoma) | 4,401.70 mi (7,083.85 km) |
| Pencoed to Owatonna (Minnesota) | 3,927.89 mi (6,321.33 km) |
| Pencoed to Owensboro (Kentucky) | 3,987.93 mi (6,417.95 km) |
| Pencoed to Owings Mills (Maryland) | 3,493.35 mi (5,622.01 km) |
| Pencoed to Owosso (Michigan) | 3,633.04 mi (5,846.82 km) |
