| Pontneddfechan to Olympia Heights (Florida) | 4,287.28 mi (6,899.72 km) |
| Pontneddfechan to Omaha (Nebraska) | 4,154.96 mi (6,686.76 km) |
| Pontneddfechan to On Top of the World Designated Place (Florida) | 4,200.17 mi (6,759.52 km) |
| Pontneddfechan to Onalaska (Wisconsin) | 3,851.05 mi (6,197.66 km) |
| Pontneddfechan to Oneida (New York) | 3,282.09 mi (5,282.02 km) |
| Pontneddfechan to Oneonta (New York) | 3,283.94 mi (5,284.99 km) |
| Pontneddfechan to Ontario (California) | 5,296.27 mi (8,523.52 km) |
| Pontneddfechan to Ontario (Oregon) | 4,721.66 mi (7,598.77 km) |
| Pontneddfechan to Opa-locka (Florida) | 4,274.86 mi (6,879.72 km) |
| Pontneddfechan to Opelika (Alabama) | 4,153.50 mi (6,684.41 km) |
| Pontneddfechan to Opelousas (Louisiana) | 4,533.32 mi (7,295.67 km) |
| Pontneddfechan to Orange (California) | 5,316.68 mi (8,556.38 km) |
| Pontneddfechan to Orange (Texas) | 4,621.53 mi (7,437.63 km) |
| Pontneddfechan to Orange City (Florida) | 4,166.68 mi (6,705.62 km) |
| Pontneddfechan to Orangeburg (South Carolina) | 3,926.83 mi (6,319.63 km) |
