| DeForest to Olympia Heights (Florida) | 1,311.83 mi (2,111.19 km) |
| DeForest to Omaha (Nebraska) | 368.99 mi (593.83 km) |
| DeForest to On Top of the World Designated Place (Florida) | 1,051.27 mi (1,691.86 km) |
| DeForest to Onalaska (Wisconsin) | 103.83 mi (167.11 km) |
| DeForest to Oneida (New York) | 688.90 mi (1,108.68 km) |
| DeForest to Oneonta (New York) | 724.35 mi (1,165.74 km) |
| DeForest to Ontario (California) | 1,642.24 mi (2,642.93 km) |
| DeForest to Ontario (Oregon) | 1,376.59 mi (2,215.41 km) |
| DeForest to Opa-locka (Florida) | 1,302.32 mi (2,095.88 km) |
| DeForest to Opelika (Alabama) | 761.30 mi (1,225.19 km) |
| DeForest to Opelousas (Louisiana) | 890.63 mi (1,433.34 km) |
| DeForest to Orange (California) | 1,661.25 mi (2,673.52 km) |
| DeForest to Orange (Texas) | 937.76 mi (1,509.19 km) |
| DeForest to Orange City (Florida) | 1,083.99 mi (1,744.51 km) |
| DeForest to Orangeburg (South Carolina) | 813.57 mi (1,309.31 km) |
