| Effingham to Odessa (Texas) | 921.56 mi (1,483.11 km) |
| Effingham to Ogden (Utah) | 1,241.01 mi (1,997.22 km) |
| Effingham to Oildale (California) | 1,687.00 mi (2,714.97 km) |
| Effingham to Ojus (Florida) | 1,031.35 mi (1,659.79 km) |
| Effingham to Okemos (Michigan) | 328.59 mi (528.82 km) |
| Effingham to Oklahoma City (Oklahoma) | 553.17 mi (890.24 km) |
| Effingham to Okmulgee (Oklahoma) | 475.52 mi (765.27 km) |
| Effingham to Olathe (Kansas) | 336.95 mi (542.26 km) |
| Effingham to Old Jamestown (Missouri) | 95.13 mi (153.09 km) |
| Effingham to Oldsmar (Florida) | 835.90 mi (1,345.26 km) |
| Effingham to Olean (New York) | 568.45 mi (914.83 km) |
| Effingham to Olive Branch (Mississippi) | 296.14 mi (476.59 km) |
| Effingham to Olivehurst (California) | 1,759.84 mi (2,832.19 km) |
| Effingham to Olney (Maryland) | 614.82 mi (989.46 km) |
| Effingham to Olympia (Washington) | 1,801.03 mi (2,898.48 km) |
