Isoko people are an ethnolinguistic group that inhabits the Isoko region of Delta State, Nigeria. They are people of southern Nigeria, near the northwestern Niger delta. Delta State is one of the 36 states of the Federal Republic of Nigeria. The Isokos speak the Isoko language, which is very linguistically similar to the Urhobo language. James W. Welch asserted that Isoko language is a dialect of Urhobo language and many people hold that opinion. The Isoko culture is related to several cultures in the Niger-Delta - namedly, Urhobo, Ijaw and Anioma. Urhobo are related in language and culture, leading to the missionaries erroneously labelling the Urhobo and Isoko cultural groups as Sobo. This name was strongly rejected by both tribes.