| Harper Woods to Oberkirch | 4,159.20 mi (6,693.58 km) |
| Harper Woods to Obernburg am Main | 4,152.36 mi (6,682.58 km) |
| Harper Woods to Obernkirchen | 4,064.91 mi (6,541.84 km) |
| Harper Woods to Oberschleissheim | 4,304.16 mi (6,926.87 km) |
| Harper Woods to Oberstdorf | 4,286.59 mi (6,898.60 km) |
| Harper Woods to Obertraubling | 4,299.42 mi (6,919.25 km) |
| Harper Woods to Obertshausen | 4,132.49 mi (6,650.60 km) |
| Harper Woods to Oberursel | 4,117.89 mi (6,627.10 km) |
| Harper Woods to Ochsenfurt | 4,194.35 mi (6,750.15 km) |
| Harper Woods to Ochsenhausen | 4,248.64 mi (6,837.52 km) |
| Harper Woods to Ochtrup | 3,996.30 mi (6,431.43 km) |
| Harper Woods to Odenthal | 4,033.61 mi (6,491.46 km) |
| Harper Woods to Oelde | 4,044.49 mi (6,508.98 km) |
| Harper Woods to Oelsnitz | 4,244.09 mi (6,830.20 km) |
| Harper Woods to Oer-Erkenschwick | 4,017.72 mi (6,465.90 km) |
