| Niceville to Olympia Heights (Florida) | 499.83 mi (804.40 km) |
| Niceville to Omaha (Nebraska) | 913.79 mi (1,470.61 km) |
| Niceville to On Top of the World Designated Place (Florida) | 269.61 mi (433.90 km) |
| Niceville to Onalaska (Wisconsin) | 958.63 mi (1,542.76 km) |
| Niceville to Oneida (New York) | 1,051.31 mi (1,691.92 km) |
| Niceville to Oneonta (New York) | 1,037.42 mi (1,669.57 km) |
| Niceville to Ontario (California) | 1,827.49 mi (2,941.06 km) |
| Niceville to Ontario (Oregon) | 1,902.93 mi (3,062.47 km) |
| Niceville to Opa-locka (Florida) | 495.51 mi (797.44 km) |
| Niceville to Opelika (Alabama) | 160.86 mi (258.89 km) |
| Niceville to Opelousas (Louisiana) | 333.66 mi (536.98 km) |
| Niceville to Orange (California) | 1,840.22 mi (2,961.54 km) |
| Niceville to Orange (Texas) | 435.35 mi (700.64 km) |
| Niceville to Orange City (Florida) | 330.06 mi (531.19 km) |
| Niceville to Orangeburg (South Carolina) | 387.04 mi (622.87 km) |
