| Pontneddfechan to Oswego (Illinois) | 3,843.39 mi (6,185.33 km) |
| Pontneddfechan to Oswego (New York) | 3,300.22 mi (5,311.20 km) |
| Pontneddfechan to Otsego (Minnesota) | 3,876.49 mi (6,238.61 km) |
| Pontneddfechan to Ottawa (Illinois) | 3,877.34 mi (6,239.98 km) |
| Pontneddfechan to Ottawa (Kansas) | 4,255.23 mi (6,848.13 km) |
| Pontneddfechan to Ottumwa (Iowa) | 4,030.41 mi (6,486.31 km) |
| Pontneddfechan to Overland (Missouri) | 4,062.16 mi (6,537.41 km) |
| Pontneddfechan to Overland Park (Kansas) | 4,219.24 mi (6,790.21 km) |
| Pontneddfechan to Overlea (Maryland) | 3,476.22 mi (5,594.43 km) |
| Pontneddfechan to Oviedo (Florida) | 4,176.17 mi (6,720.89 km) |
| Pontneddfechan to Owasso (Oklahoma) | 4,391.45 mi (7,067.36 km) |
| Pontneddfechan to Owatonna (Minnesota) | 3,916.59 mi (6,303.15 km) |
| Pontneddfechan to Owensboro (Kentucky) | 3,978.71 mi (6,403.11 km) |
| Pontneddfechan to Owings Mills (Maryland) | 3,485.37 mi (5,609.16 km) |
| Pontneddfechan to Owosso (Michigan) | 3,623.12 mi (5,830.85 km) |
