Efik  proper, wrongly referred to as Riverain Ibibio, is the native language of the Efik people of Nigeria, where it is a national language. It is the official language of Cross River State in Nigeria.
The language Efik can be understood by the Ibibio speaking people of Akwa Ibom state (a neighboring state to Cross River State) and often thought of as the same language by non-speakers.
- ^ Efik at Ethnologue (18th ed., 2015)
- ^ Efik language at Ethnologue (14th ed., 2000).
- ^ Nordhoff, Sebastian; Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2013). "Efik". Glottolog. Leipzig: Max Planck Institute for Evolutionary Anthropology.
- ^ Laurie Bauer, 2007, The Linguistics Student’s Handbook, Edinburgh
- ^ Okon E. Essien, 1986, Ibibio names: their structure and their meanings