| Diamond Bar to Opole | 5,996.13 mi (9,649.84 km) |
| Diamond Bar to Orzesze | 6,046.01 mi (9,730.12 km) |
| Diamond Bar to Osowa | 5,797.09 mi (9,329.51 km) |
| Diamond Bar to Ostroda | 5,872.88 mi (9,451.49 km) |
| Diamond Bar to Ostroleka | 5,945.69 mi (9,568.67 km) |
| Diamond Bar to Ostrow Mazowiecka | 5,968.70 mi (9,605.69 km) |
| Diamond Bar to Ostrow Wielkopolski | 5,937.89 mi (9,556.11 km) |
| Diamond Bar to Ostrowiec Swietokrzyski | 6,065.78 mi (9,761.94 km) |
| Diamond Bar to Ostrzeszow | 5,953.90 mi (9,581.88 km) |
| Diamond Bar to Oswiecim | 6,064.25 mi (9,759.46 km) |
| Diamond Bar to Otwock | 5,994.01 mi (9,646.42 km) |
| Diamond Bar to Ozarow Mazowiecki | 5,977.41 mi (9,619.72 km) |
| Diamond Bar to Ozimek | 6,002.85 mi (9,660.65 km) |
| Diamond Bar to Ozorkow | 5,955.87 mi (9,585.04 km) |
| Diamond Bar to Pabianice | 5,976.33 mi (9,617.98 km) |
