| Mercerville to Olympia Heights (Florida) | 1,054.12 mi (1,696.44 km) |
| Mercerville to Omaha (Nebraska) | 1,117.54 mi (1,798.51 km) |
| Mercerville to On Top of the World Designated Place (Florida) | 880.99 mi (1,417.81 km) |
| Mercerville to Onalaska (Wisconsin) | 882.24 mi (1,419.83 km) |
| Mercerville to Oneida (New York) | 202.58 mi (326.01 km) |
| Mercerville to Oneonta (New York) | 154.55 mi (248.73 km) |
| Mercerville to Ontario (California) | 2,378.61 mi (3,828.00 km) |
| Mercerville to Ontario (Oregon) | 2,158.50 mi (3,473.78 km) |
| Mercerville to Opa-locka (Florida) | 1,041.00 mi (1,675.33 km) |
| Mercerville to Opelika (Alabama) | 790.49 mi (1,272.16 km) |
| Mercerville to Opelousas (Louisiana) | 1,183.89 mi (1,905.28 km) |
| Mercerville to Orange (California) | 2,396.39 mi (3,856.62 km) |
| Mercerville to Orange (Texas) | 1,279.41 mi (2,059.01 km) |
| Mercerville to Orange City (Florida) | 865.64 mi (1,393.12 km) |
| Mercerville to Orangeburg (South Carolina) | 577.24 mi (928.97 km) |
