Osun is an inland state in south-western Nigeria. Its capital is Osogbo.

The modern Osun State was created in August 27, 1991 from part of the old Oyo State. The state’s name is derived from the River Osun, the venerated natural spring that is the manifestation of the Yoruba goddess of the same name.

Important cultural events in the state include the Ori Oke and Egungun festival in Iragbiji, Olojo in Ife and the Osun Osogbo festival.

Every year, adherents and non-adherents of Osun, one of the Orisa (the traditional deities of the Yoruba people), travel from all over the world to attend the annual Osun-Osogbo festival in August. Visitors include nationals of Brazil, Cuba, Trinidad, Grenada, and other nations in the Americas with a significant Yoruba cultural heritage. Annual traditional festivities and invocations of the Osun goddess are held along the banks of the river bearing her name into which – according to Yoruba Oratory traditions – she transformed.

Ọsun-Ọsogbo Groove, the shrine of the annual rites of the deity and an important artistic center, was declared a World Heritage Site in 2005