| Williamsport to Odenton (Maryland) | 151.28 mi (243.47 km) |
| Williamsport to Odessa (Texas) | 1,538.76 mi (2,476.39 km) |
| Williamsport to Ogden (Utah) | 1,802.57 mi (2,900.96 km) |
| Williamsport to Oildale (California) | 2,288.37 mi (3,682.77 km) |
| Williamsport to Ojus (Florida) | 1,070.98 mi (1,723.57 km) |
| Williamsport to Okemos (Michigan) | 392.07 mi (630.98 km) |
| Williamsport to Oklahoma City (Oklahoma) | 1,175.55 mi (1,891.87 km) |
| Williamsport to Okmulgee (Oklahoma) | 1,095.10 mi (1,762.40 km) |
| Williamsport to Olathe (Kansas) | 952.62 mi (1,533.09 km) |
| Williamsport to Old Jamestown (Missouri) | 719.35 mi (1,157.68 km) |
| Williamsport to Oldsmar (Florida) | 965.32 mi (1,553.53 km) |
| Williamsport to Olean (New York) | 92.57 mi (148.98 km) |
| Williamsport to Olive Branch (Mississippi) | 819.24 mi (1,318.44 km) |
| Williamsport to Olivehurst (California) | 2,329.78 mi (3,749.42 km) |
| Williamsport to Olney (Maryland) | 144.65 mi (232.79 km) |
