Evidence suggests that ethnic identity and ethnic diversity in Africa have empirical relationships with her historical past and colonial experiences. This chapter examines these summative experiences to underscore the role the colonialist played in ethnic-identity formation, classification, and discrimination and the elevation of ethnicity as a political and economic resource for nation-building. The colonialists constructed ethnic identities where none existed and promoted them to a level of political consciousness, leaving behind legacy of political control and domination, as is evident in Rwanda, Kenya, Nigeria, and South Sudan, among African nations. Lessons are drawn from Arendt Lijphart’sthesis on the consociational model of sharing power to explain the relationships between ethnicity and the corresponding power relations that induce ethnic conflicts in Africa. A call is made to African leaders to promote social harmony, equity, fairness, and social justice in governance and national unity.