| Port Talbot to Olympia Heights (Florida) | 4,279.68 mi (6,887.49 km) |
| Port Talbot to Omaha (Nebraska) | 4,152.82 mi (6,683.32 km) |
| Port Talbot to On Top of the World Designated Place (Florida) | 4,193.47 mi (6,748.74 km) |
| Port Talbot to Onalaska (Wisconsin) | 3,848.76 mi (6,193.99 km) |
| Port Talbot to Oneida (New York) | 3,277.38 mi (5,274.44 km) |
| Port Talbot to Oneonta (New York) | 3,278.98 mi (5,277.01 km) |
| Port Talbot to Ontario (California) | 5,296.38 mi (8,523.70 km) |
| Port Talbot to Ontario (Oregon) | 4,723.25 mi (7,601.34 km) |
| Port Talbot to Opa-locka (Florida) | 4,267.27 mi (6,867.51 km) |
| Port Talbot to Opelika (Alabama) | 4,147.96 mi (6,675.49 km) |
| Port Talbot to Opelousas (Louisiana) | 4,528.47 mi (7,287.88 km) |
| Port Talbot to Orange (California) | 5,316.80 mi (8,556.56 km) |
| Port Talbot to Orange (Texas) | 4,616.89 mi (7,430.17 km) |
| Port Talbot to Orange City (Florida) | 4,159.79 mi (6,694.53 km) |
| Port Talbot to Orangeburg (South Carolina) | 3,920.74 mi (6,309.82 km) |
