Rivers State is the sixth-largest geographic area in Nigeria according to 2006 census data.^[1] The state has an indigenously diverse population with major riverine and upland divisions. The dominant tribes are: Ogoni, Kalabari and Ikwerre.^[2] representing three dominant Ethno-Linguistic blocs in the State, in no particular order (Ogoni, Ijoid and Igboid). Upland Rivers State covering about 45% is composed mainly of Ogoni and Igbo-speaking people. The riverine, including most of the state's towns and villages surrounded by water, is moderately inhabited. It covers approximately 39% of the total land mass and is home to the Ijaw .^[3]

This list refers to the various autochthonous ethnic groups residing within Rivers State's boundaries in addition to its upland and riverine areas.