| Apex to Oswego (Illinois) | 654.97 mi (1,054.07 km) |
| Apex to Oswego (New York) | 548.63 mi (882.94 km) |
| Apex to Otsego (Minnesota) | 1,014.47 mi (1,632.63 km) |
| Apex to Ottawa (Illinois) | 663.11 mi (1,067.17 km) |
| Apex to Ottawa (Kansas) | 922.70 mi (1,484.95 km) |
| Apex to Ottumwa (Iowa) | 818.60 mi (1,317.41 km) |
| Apex to Overland (Missouri) | 664.48 mi (1,069.38 km) |
| Apex to Overland Park (Kansas) | 894.82 mi (1,440.07 km) |
| Apex to Overlea (Maryland) | 282.71 mi (454.97 km) |
| Apex to Oviedo (Florida) | 506.53 mi (815.18 km) |
| Apex to Owasso (Oklahoma) | 947.37 mi (1,524.64 km) |
| Apex to Owatonna (Minnesota) | 953.31 mi (1,534.20 km) |
| Apex to Owensboro (Kentucky) | 477.34 mi (768.21 km) |
| Apex to Owings Mills (Maryland) | 279.15 mi (449.25 km) |
| Apex to Owosso (Michigan) | 576.46 mi (927.72 km) |
