| Altoona to Olympia Heights (Florida) | 1,027.55 mi (1,653.68 km) |
| Altoona to Omaha (Nebraska) | 921.96 mi (1,483.75 km) |
| Altoona to On Top of the World Designated Place (Florida) | 817.85 mi (1,316.20 km) |
| Altoona to Onalaska (Wisconsin) | 695.00 mi (1,118.49 km) |
| Altoona to Oneida (New York) | 226.69 mi (364.82 km) |
| Altoona to Oneonta (New York) | 218.78 mi (352.10 km) |
| Altoona to Ontario (California) | 2,182.79 mi (3,512.87 km) |
| Altoona to Ontario (Oregon) | 1,969.11 mi (3,168.97 km) |
| Altoona to Opa-locka (Florida) | 1,014.96 mi (1,633.41 km) |
| Altoona to Opelika (Alabama) | 665.63 mi (1,071.23 km) |
| Altoona to Opelousas (Louisiana) | 1,031.01 mi (1,659.25 km) |
| Altoona to Orange (California) | 2,200.63 mi (3,541.57 km) |
| Altoona to Orange (Texas) | 1,121.68 mi (1,805.17 km) |
| Altoona to Orange City (Florida) | 816.15 mi (1,313.46 km) |
| Altoona to Orangeburg (South Carolina) | 503.40 mi (810.14 km) |
