| Johnstown to Oswego (Illinois) | 499.66 mi (804.13 km) |
| Johnstown to Oswego (New York) | 249.21 mi (401.06 km) |
| Johnstown to Otsego (Minnesota) | 818.14 mi (1,316.67 km) |
| Johnstown to Ottawa (Illinois) | 522.40 mi (840.72 km) |
| Johnstown to Ottawa (Kansas) | 878.68 mi (1,414.09 km) |
| Johnstown to Ottumwa (Iowa) | 708.32 mi (1,139.92 km) |
| Johnstown to Overland (Missouri) | 620.15 mi (998.04 km) |
| Johnstown to Overland Park (Kansas) | 844.07 mi (1,358.41 km) |
| Johnstown to Overlea (Maryland) | 143.70 mi (231.26 km) |
| Johnstown to Oviedo (Florida) | 816.37 mi (1,313.83 km) |
| Johnstown to Owasso (Oklahoma) | 956.67 mi (1,539.61 km) |
| Johnstown to Owatonna (Minnesota) | 776.03 mi (1,248.90 km) |
| Johnstown to Owensboro (Kentucky) | 474.13 mi (763.04 km) |
| Johnstown to Owings Mills (Maryland) | 129.33 mi (208.14 km) |
| Johnstown to Owosso (Michigan) | 327.99 mi (527.85 km) |
