| Monroe to Oswego (Illinois) | 665.74 mi (1,071.41 km) |
| Monroe to Oswego (New York) | 1,132.40 mi (1,822.42 km) |
| Monroe to Otsego (Minnesota) | 884.62 mi (1,423.65 km) |
| Monroe to Ottawa (Illinois) | 636.29 mi (1,024.02 km) |
| Monroe to Ottawa (Kansas) | 456.65 mi (734.91 km) |
| Monroe to Ottumwa (Iowa) | 587.66 mi (945.75 km) |
| Monroe to Overland (Missouri) | 437.50 mi (704.08 km) |
| Monroe to Overland Park (Kansas) | 463.68 mi (746.22 km) |
| Monroe to Overlea (Maryland) | 988.63 mi (1,591.05 km) |
| Monroe to Oviedo (Florida) | 700.04 mi (1,126.60 km) |
| Monroe to Owasso (Oklahoma) | 337.00 mi (542.36 km) |
| Monroe to Owatonna (Minnesota) | 802.02 mi (1,290.72 km) |
| Monroe to Owensboro (Kentucky) | 457.63 mi (736.48 km) |
| Monroe to Owings Mills (Maryland) | 976.62 mi (1,571.72 km) |
| Monroe to Owosso (Michigan) | 841.87 mi (1,354.86 km) |
