| Idar-Oberstein to Olympia Heights (Florida) | 4,781.92 mi (7,695.76 km) |
| Idar-Oberstein to Omaha (Nebraska) | 4,629.35 mi (7,450.22 km) |
| Idar-Oberstein to On Top of the World Designated Place (Florida) | 4,696.71 mi (7,558.62 km) |
| Idar-Oberstein to Onalaska (Wisconsin) | 4,327.19 mi (6,963.93 km) |
| Idar-Oberstein to Oneida (New York) | 3,775.13 mi (6,075.48 km) |
| Idar-Oberstein to Oneonta (New York) | 3,777.92 mi (6,079.97 km) |
| Idar-Oberstein to Ontario (California) | 5,741.18 mi (9,239.53 km) |
| Idar-Oberstein to Ontario (Oregon) | 5,143.53 mi (8,277.71 km) |
| Idar-Oberstein to Opa-locka (Florida) | 4,769.55 mi (7,675.86 km) |
| Idar-Oberstein to Opelika (Alabama) | 4,649.11 mi (7,482.01 km) |
| Idar-Oberstein to Opelousas (Louisiana) | 5,026.66 mi (8,089.62 km) |
| Idar-Oberstein to Orange (California) | 5,761.53 mi (9,272.28 km) |
| Idar-Oberstein to Orange (Texas) | 5,113.95 mi (8,230.11 km) |
| Idar-Oberstein to Orange City (Florida) | 4,663.01 mi (7,504.39 km) |
| Idar-Oberstein to Orangeburg (South Carolina) | 4,423.34 mi (7,118.67 km) |
