| Rock Island to Olympia (Washington) | 1,632.22 mi (2,626.80 km) |
| Rock Island to Olympia Heights (Florida) | 1,235.23 mi (1,987.90 km) |
| Rock Island to Omaha (Nebraska) | 283.97 mi (457.00 km) |
| Rock Island to On Top of the World Designated Place (Florida) | 972.85 mi (1,565.66 km) |
| Rock Island to Onalaska (Wisconsin) | 170.08 mi (273.72 km) |
| Rock Island to Oneida (New York) | 769.80 mi (1,238.87 km) |
| Rock Island to Oneonta (New York) | 798.94 mi (1,285.77 km) |
| Rock Island to Ontario (California) | 1,555.32 mi (2,503.04 km) |
| Rock Island to Ontario (Oregon) | 1,344.89 mi (2,164.40 km) |
| Rock Island to Opa-locka (Florida) | 1,226.59 mi (1,974.00 km) |
| Rock Island to Opelika (Alabama) | 672.56 mi (1,082.38 km) |
| Rock Island to Opelousas (Louisiana) | 760.80 mi (1,224.38 km) |
| Rock Island to Orange (California) | 1,573.77 mi (2,532.75 km) |
| Rock Island to Orange (Texas) | 803.83 mi (1,293.64 km) |
| Rock Island to Orange City (Florida) | 1,011.20 mi (1,627.37 km) |
