Koidu is a city in Sierra Leone. Koidu may also refer to one of several villages in Estonia: Koidu, Harju County, village in Saue Parish, Harju County Koidu, Lääne County, village in Ridala Parish, Lääne County Koidu, Saare County, village in Kaarma Parish, Saare County Koidu, Viljandi County, village in Tarvastu Parish, Viljandi County See also Koidu-Ellavere, village in Koeru Parish, Järva County, Estonia