Nigeria as a country is characterized by a lopsided political structure and sentiments of ethnic politics that stand to hurt the existence of a just society. These foundational challenges make the impossibility of a democratic community capable of ensuring Nigeria's political and socio-economic progress uncertain. Hence, this study undertakes a critical examination of Rawls' theory of justice, employing its assumptions to mirror Nigeria’s political instability and ethnic crises phenomena to gather its embedded lessons, primarily to enhance social justice, ethnic relationships, and political stability. The method employed in this paper is critical analysis, which is used to analyze the crises of social justice, ethnic crises, and issues of political instability in Nigeria. This paper also philosophically considers the relevance of John Rawls' theory of justice and attempts to establish its applicability to Nigeria’s political structure that would uphold her stability, ethnic relationships, and a healthy political structure that has been bedeviled by numerous challenges of social justice and political instability.