| Porthcawl to Oswego (Illinois) | 3,847.71 mi (6,192.29 km) |
| Porthcawl to Oswego (New York) | 3,302.78 mi (5,315.31 km) |
| Porthcawl to Otsego (Minnesota) | 3,882.87 mi (6,248.88 km) |
| Porthcawl to Ottawa (Illinois) | 3,881.66 mi (6,246.93 km) |
| Porthcawl to Ottawa (Kansas) | 4,260.09 mi (6,855.96 km) |
| Porthcawl to Ottumwa (Iowa) | 4,035.35 mi (6,494.27 km) |
| Porthcawl to Overland (Missouri) | 4,066.02 mi (6,543.63 km) |
| Porthcawl to Overland Park (Kansas) | 4,224.06 mi (6,797.96 km) |
| Porthcawl to Overlea (Maryland) | 3,477.33 mi (5,596.23 km) |
| Porthcawl to Oviedo (Florida) | 4,175.12 mi (6,719.20 km) |
| Porthcawl to Owasso (Oklahoma) | 4,395.83 mi (7,074.41 km) |
| Porthcawl to Owatonna (Minnesota) | 3,922.57 mi (6,312.76 km) |
| Porthcawl to Owensboro (Kentucky) | 3,981.61 mi (6,407.78 km) |
| Porthcawl to Owings Mills (Maryland) | 3,486.56 mi (5,611.07 km) |
| Porthcawl to Owosso (Michigan) | 3,627.03 mi (5,837.14 km) |
