The aim of this paper is to examine the origins, structure and features of Nigerian Federalism. The paper traces the origin of Nigerian federalism to colonial insinuations of conquest and divide and rule. Colonialism began with the reorganization and fusion of territories known as amalgamation between 1861 and 1914, an act which was not meant to nurture a federal idea. The finding of this paper reveals that, Nigerian federalism is a child of necessity rather than a colonial intention for the country. The colonial conquest had altered the symbiotic and inter-group relationships that had existed and persisted between the diverse cultures and people. This was replaced by enmity, divisions and hatred with strong sense of sectionalism, ethno-religious, tribal chauvinism and geographical polarizations. Ever since 1914 to date, the structure of Nigerian federalism has dramatically transformed from the level of provinces and regions to the current structure of 36 States and 774 Local Government Areas as well as the Federal Capital Territory, Abuja. The challenges that are facing Nigerian federalism are; revenue sharing formula among the tiers, state creation, resource control and power sharing. The paper utilizes the secondary source of data and analysis of documents as its methodology. The paper concludes that Nigerians have recognized the significance of the federal system of government and opt for its preservation, because it encourages unity in diversity among the 250 ethnic groups that make up the federation.