| Forney to Olympia Heights (Florida) | 1,084.17 mi (1,744.80 km) |
| Forney to Omaha (Nebraska) | 589.00 mi (947.90 km) |
| Forney to On Top of the World Designated Place (Florida) | 875.65 mi (1,409.22 km) |
| Forney to Onalaska (Wisconsin) | 820.36 mi (1,320.25 km) |
| Forney to Oneida (New York) | 1,333.79 mi (2,146.53 km) |
| Forney to Oneonta (New York) | 1,343.77 mi (2,162.59 km) |
| Forney to Ontario (California) | 1,221.41 mi (1,965.66 km) |
| Forney to Ontario (Oregon) | 1,351.45 mi (2,174.95 km) |
| Forney to Opa-locka (Florida) | 1,082.60 mi (1,742.28 km) |
| Forney to Opelika (Alabama) | 643.70 mi (1,035.94 km) |
| Forney to Opelousas (Louisiana) | 299.34 mi (481.73 km) |
| Forney to Orange (California) | 1,234.36 mi (1,986.50 km) |
| Forney to Orange (Texas) | 240.80 mi (387.53 km) |
| Forney to Orange City (Florida) | 936.35 mi (1,506.91 km) |
| Forney to Orangeburg (South Carolina) | 902.56 mi (1,452.54 km) |
