| Des Moines to Olympia Heights (Florida) | 1,331.27 mi (2,142.47 km) |
| Des Moines to Omaha (Nebraska) | 128.34 mi (206.55 km) |
| Des Moines to On Top of the World Designated Place (Florida) | 1,069.96 mi (1,721.93 km) |
| Des Moines to Onalaska (Wisconsin) | 201.17 mi (323.75 km) |
| Des Moines to Oneida (New York) | 920.95 mi (1,482.12 km) |
| Des Moines to Oneonta (New York) | 952.01 mi (1,532.11 km) |
| Des Moines to Ontario (California) | 1,403.71 mi (2,259.05 km) |
| Des Moines to Ontario (Oregon) | 1,192.51 mi (1,919.17 km) |
| Des Moines to Opa-locka (Florida) | 1,323.65 mi (2,130.22 km) |
| Des Moines to Opelika (Alabama) | 763.95 mi (1,229.46 km) |
| Des Moines to Opelousas (Louisiana) | 768.02 mi (1,236.01 km) |
| Des Moines to Orange (California) | 1,422.40 mi (2,289.13 km) |
| Des Moines to Orange (Texas) | 791.16 mi (1,273.24 km) |
| Des Moines to Orange City (Florida) | 1,113.68 mi (1,792.30 km) |
| Des Moines to Orangeburg (South Carolina) | 892.29 mi (1,436.00 km) |
