The political changes demanded by the countries with a colonial past in their independence processes are shaped in line with their historical realities. Demands for political change have intensified as the change of domination apparatuses and ideologies have been determinant in achieving political demands, and nationalism has an important place among them. Nationalism is a concept that has modern characteristics and carries functional elements with its ideological modernity in terms of its capacity to meet demands. Nationalism is one of the tools used especially to realize the demands for political power. Another tool is political violence, which is used to implement the practices preferred within the framework of the said ideology. In terms of their instrumental relations, nationalism and political violence are phenomena that form clusters of mutual interests and feed each other. Sri Lanka was one of the places where these phenomena were experienced together. The study aims to examine the nationalism used in the politicization tendencies of the Sinhala ethnicity and Tamil ethnicity trying to make room for itself on the island after independence, and the political violence that emerged after its instrumentalization, with an instrumentalist approach.