| Iowa City to Oerlinghausen | 4,405.87 mi (7,090.56 km) |
| Iowa City to Oestrich-Winkel | 4,460.34 mi (7,178.22 km) |
| Iowa City to Offenburg | 4,519.55 mi (7,273.51 km) |
| Iowa City to Oftersheim | 4,506.91 mi (7,253.17 km) |
| Iowa City to Ohrdruf | 4,524.11 mi (7,280.86 km) |
| Iowa City to Ohringen | 4,547.16 mi (7,317.95 km) |
| Iowa City to Olbernhau | 4,621.15 mi (7,437.02 km) |
| Iowa City to Olching | 4,654.92 mi (7,491.36 km) |
| Iowa City to Oldenburg | 4,344.07 mi (6,991.11 km) |
| Iowa City to Oldenburg in Holstein | 4,388.16 mi (7,062.06 km) |
| Iowa City to Olfen | 4,370.58 mi (7,033.76 km) |
| Iowa City to Olpe | 4,413.99 mi (7,103.62 km) |
| Iowa City to Olsberg | 4,423.87 mi (7,119.54 km) |
| Iowa City to Oranienburg | 4,529.34 mi (7,289.27 km) |
| Iowa City to Ortenberg | 4,484.03 mi (7,216.35 km) |
