| On Top of the World Designated Place to Oswego (Illinois) | 932.81 mi (1,501.21 km) |
| On Top of the World Designated Place to Oswego (New York) | 1,041.58 mi (1,676.26 km) |
| On Top of the World Designated Place to Otsego (Minnesota) | 1,276.08 mi (2,053.65 km) |
| On Top of the World Designated Place to Ottawa (Illinois) | 922.61 mi (1,484.80 km) |
| On Top of the World Designated Place to Ottawa (Kansas) | 990.46 mi (1,594.00 km) |
| On Top of the World Designated Place to Ottumwa (Iowa) | 1,001.35 mi (1,611.52 km) |
| On Top of the World Designated Place to Overland (Missouri) | 807.87 mi (1,300.14 km) |
| On Top of the World Designated Place to Overland Park (Kansas) | 978.66 mi (1,575.01 km) |
| On Top of the World Designated Place to Overlea (Maryland) | 781.19 mi (1,257.20 km) |
| On Top of the World Designated Place to Oviedo (Florida) | 73.36 mi (118.06 km) |
| On Top of the World Designated Place to Owasso (Oklahoma) | 929.41 mi (1,495.74 km) |
| On Top of the World Designated Place to Owatonna (Minnesota) | 1,197.75 mi (1,927.59 km) |
| On Top of the World Designated Place to Owensboro (Kentucky) | 659.21 mi (1,060.90 km) |
| On Top of the World Designated Place to Owings Mills (Maryland) | 777.72 mi (1,251.61 km) |
| On Top of the World Designated Place to Owosso (Michigan) | 965.40 mi (1,553.66 km) |
