| McKeesport to Olympia Heights (Florida) | 1,010.39 mi (1,626.07 km) |
| McKeesport to Omaha (Nebraska) | 848.90 mi (1,366.17 km) |
| McKeesport to On Top of the World Designated Place (Florida) | 788.53 mi (1,269.02 km) |
| McKeesport to Onalaska (Wisconsin) | 631.17 mi (1,015.78 km) |
| McKeesport to Oneida (New York) | 286.70 mi (461.40 km) |
| McKeesport to Oneonta (New York) | 287.39 mi (462.50 km) |
| McKeesport to Ontario (California) | 2,107.01 mi (3,390.90 km) |
| McKeesport to Ontario (Oregon) | 1,901.73 mi (3,060.53 km) |
| McKeesport to Opa-locka (Florida) | 998.13 mi (1,606.34 km) |
| McKeesport to Opelika (Alabama) | 612.90 mi (986.37 km) |
| McKeesport to Opelousas (Louisiana) | 964.95 mi (1,552.94 km) |
| McKeesport to Orange (California) | 2,124.78 mi (3,419.51 km) |
| McKeesport to Orange (Texas) | 1,053.72 mi (1,695.79 km) |
| McKeesport to Orange City (Florida) | 792.38 mi (1,275.21 km) |
| McKeesport to Orangeburg (South Carolina) | 476.57 mi (766.97 km) |
