Onitsha (Igbo: Ọ̀nị̀chà Mmílí or just Ọ̀nị̀chà) is a city located on the eastern bank of the Niger River, in Nigeria's Anambra State. A metropolitan city, Onitsha is known for its river port and as an economic hub for commerce, industry, and education.
It hosts the Onitsha Main Market, the largest market in Africa in terms of geographical size and volume of goods. In the 2006 Nigerian census, Onitsha had an estimated city proper population of over quarter a million people, and, as of 2016, had an estimated urban population of 7,425,000. The indigenous people of Onitsha are Igbo and speak the Igbo language. The Onitsha people are referred to as Ndi Onicha. Onitsha Mmili was known as Ado N'Idu by migrants who departed from the vicinity of the Kingdom of Benin near the far western portion of Igboland (near what is now Agbor), after a violent dispute with the Oba of Benin that can be tentatively dated to the early 1500s. These migrants traveled eastward through what is now Western Igboland and various towns also called "Onitsha", for example Onicha-Ugbo, "farmland-Onitsha". Folklore has it that, Onitsha was founded by one of the sons of Chima, the founder of Issele-Uku kingdom in western Igboland.