| Effingham to Oakley (California) | 1,782.53 mi (2,868.71 km) |
| Effingham to Oakton (Virginia) | 603.82 mi (971.76 km) |
| Effingham to Oakville (Missouri) | 106.00 mi (170.60 km) |
| Effingham to Oatfield (Oregon) | 1,779.71 mi (2,864.17 km) |
| Effingham to Ocala (Florida) | 777.81 mi (1,251.76 km) |
| Effingham to Ocean Acres (New Jersey) | 761.97 mi (1,226.27 km) |
| Effingham to Ocean City (New Jersey) | 746.26 mi (1,200.99 km) |
| Effingham to Ocean Pines (Maryland) | 723.27 mi (1,163.99 km) |
| Effingham to Ocean Pointe (Hawaii) | 4,224.16 mi (6,798.12 km) |
| Effingham to Ocean Springs (Mississippi) | 602.11 mi (969.00 km) |
| Effingham to Oceanside (California) | 1,647.30 mi (2,651.07 km) |
| Effingham to Oceanside (New York) | 796.72 mi (1,282.19 km) |
| Effingham to Ocoee (Florida) | 831.53 mi (1,338.22 km) |
| Effingham to Oconomowoc (Wisconsin) | 274.94 mi (442.48 km) |
| Effingham to Odenton (Maryland) | 635.39 mi (1,022.57 km) |
