| Johnstown to Odessa (Texas) | 1,426.27 mi (2,295.36 km) |
| Johnstown to Ogden (Utah) | 1,719.83 mi (2,767.80 km) |
| Johnstown to Oildale (California) | 2,194.56 mi (3,531.80 km) |
| Johnstown to Ojus (Florida) | 995.41 mi (1,601.96 km) |
| Johnstown to Okemos (Michigan) | 328.27 mi (528.30 km) |
| Johnstown to Oklahoma City (Oklahoma) | 1,065.52 mi (1,714.79 km) |
| Johnstown to Okmulgee (Oklahoma) | 984.10 mi (1,583.76 km) |
| Johnstown to Olathe (Kansas) | 851.13 mi (1,369.76 km) |
| Johnstown to Old Jamestown (Missouri) | 613.41 mi (987.19 km) |
| Johnstown to Oldsmar (Florida) | 874.57 mi (1,407.49 km) |
| Johnstown to Olean (New York) | 123.94 mi (199.46 km) |
| Johnstown to Olive Branch (Mississippi) | 702.63 mi (1,130.78 km) |
| Johnstown to Olivehurst (California) | 2,246.04 mi (3,614.65 km) |
| Johnstown to Olney (Maryland) | 127.59 mi (205.34 km) |
| Johnstown to Olympia (Washington) | 2,215.27 mi (3,565.13 km) |
