| Monroe to Odessa (Texas) | 601.68 mi (968.32 km) |
| Monroe to Ogden (Utah) | 1,249.06 mi (2,010.17 km) |
| Monroe to Oildale (California) | 1,552.55 mi (2,498.59 km) |
| Monroe to Ojus (Florida) | 848.67 mi (1,365.80 km) |
| Monroe to Okemos (Michigan) | 818.53 mi (1,317.30 km) |
| Monroe to Oklahoma City (Oklahoma) | 372.06 mi (598.77 km) |
| Monroe to Okmulgee (Oklahoma) | 310.28 mi (499.35 km) |
| Monroe to Olathe (Kansas) | 465.84 mi (749.70 km) |
| Monroe to Old Jamestown (Missouri) | 448.14 mi (721.22 km) |
| Monroe to Oldsmar (Florida) | 640.19 mi (1,030.29 km) |
| Monroe to Olean (New York) | 997.25 mi (1,604.91 km) |
| Monroe to Olive Branch (Mississippi) | 211.89 mi (341.00 km) |
| Monroe to Olivehurst (California) | 1,704.72 mi (2,743.48 km) |
| Monroe to Olney (Maryland) | 955.44 mi (1,537.63 km) |
| Monroe to Olympia (Washington) | 1,900.96 mi (3,059.31 km) |
