Ethnicity and ethnicism is a matter of great concern to Nigeria and her citizenry. This hydra headed monsters have eaten deep into the fabrics of Nigeria nation, has been demonized and mismanaged by Nigerians and her ruling elites. Sardonically ethnicity has failed to ameliorate the status of Nigeria and her citizenry rather, it is gradually breaking the nation into different fragments, as these has created a social change in Nigeria, as Nigerians now see themselves first from their ethnic origins or groups before seeing themselves as Nigeria. Furthermore, Nigeria nation today is bedeviled with ethnic conflicts and confrontations, nepotism, cronyism, favouratism and patronage which implications has created a Mephistophelean, repugnant and gigantic wound in the nation that can’t be healed in a hurry. This research paper critically X-ray ethnicity and ethnicism in Africa under which Nigeria was the focus. Thus, the research paper went further too succinctly examine the concept of ethnicity and ethnicism by different scholars and authors among others. However, an abridged origin and manifestations of ethnicity and ethnicism were critically discussed and some recommendations were advanced at the end of its conclusion.