| Darby to Oswego (Illinois) | 693.95 mi (1,116.80 km) |
| Darby to Oswego (New York) | 252.18 mi (405.84 km) |
| Darby to Otsego (Minnesota) | 1,001.38 mi (1,611.56 km) |
| Darby to Ottawa (Illinois) | 717.34 mi (1,154.45 km) |
| Darby to Ottawa (Kansas) | 1,071.72 mi (1,724.77 km) |
| Darby to Ottumwa (Iowa) | 903.57 mi (1,454.15 km) |
| Darby to Overland (Missouri) | 811.11 mi (1,305.36 km) |
| Darby to Overland Park (Kansas) | 1,037.51 mi (1,669.72 km) |
| Darby to Overlea (Maryland) | 77.13 mi (124.13 km) |
| Darby to Oviedo (Florida) | 848.01 mi (1,364.74 km) |
| Darby to Owasso (Oklahoma) | 1,143.43 mi (1,840.17 km) |
| Darby to Owatonna (Minnesota) | 964.27 mi (1,551.84 km) |
| Darby to Owensboro (Kentucky) | 654.80 mi (1,053.80 km) |
| Darby to Owings Mills (Maryland) | 88.68 mi (142.71 km) |
| Darby to Owosso (Michigan) | 507.81 mi (817.24 km) |
