| Harwich to Opole | 723.71 mi (1,164.69 km) |
| Harwich to Orzesze | 767.55 mi (1,235.25 km) |
| Harwich to Osowa | 730.92 mi (1,176.30 km) |
| Harwich to Ostroda | 788.00 mi (1,268.16 km) |
| Harwich to Ostroleka | 854.55 mi (1,375.27 km) |
| Harwich to Ostrow Mazowiecka | 869.57 mi (1,399.43 km) |
| Harwich to Ostrow Wielkopolski | 706.04 mi (1,136.26 km) |
| Harwich to Ostrowiec Swietokrzyski | 867.21 mi (1,395.65 km) |
| Harwich to Ostrzeszow | 713.45 mi (1,148.19 km) |
| Harwich to Oswiecim | 789.77 mi (1,271.02 km) |
| Harwich to Otwock | 847.71 mi (1,364.26 km) |
| Harwich to Ozarow Mazowiecki | 827.26 mi (1,331.34 km) |
| Harwich to Ozimek | 735.52 mi (1,183.71 km) |
| Harwich to Ozorkow | 765.31 mi (1,231.64 km) |
| Harwich to Pabianice | 772.50 mi (1,243.22 km) |
