Ogun State is a state in southwestern Nigeria. Created in February 1976 from the former Western State. Ogun State borders Lagos State to the south, Oyo State and Osun State to the north, Ondo State, and the Republic of Benin to the west. Abeokuta is both Ogun State's capital and most populous city; other important cities in the state include Ijebu Ode, the former royal capital of the Ijebu Kingdom, and Sagamu, Nigeria's leading kola nut grower. Ogun state is covered predominantly by rain forest and has wooden savanna in the northwest . Ogun State had a total population of 3,751,140 residents as of 2006.

Nicknamed the "Gateway to Nigeria", the state is notable for having a high concentration of industrial estates and being a major manufacturing hub in Nigeria. Major factories in Ogun include the Dangote Cement factory in Ibese, Nestle, Lafarge Cement factory in Ewekoro, Memmcol in Orimerunmu, Coleman Cables in Sagamu and Arepo, Procter & Gamble in Agbara, amongst others.

Ogun State is predominantly Yoruba, with the Yoruba language serving as the lingua franca of the state. Ogun State is noted for being the almost exclusive site of Ofada rice production. Ogun is also home to many icons in Nigeria in particular and Africa in general.