Using Lipset and Rokkan's cleavage theory in an Indigenous context, the article compares political cleavages in internal Sami politics in Norway and Sweden. The authors discuss the historical legacies of each country's policies toward the Sami and subsequent development of party systems before using survey data to analyze cleavages within the Sami electorates. The analysis shows a prominent cleavage in Sami politics in Norway regarding the extent of Sami self-determination, whereas the main cleavage in Sweden can be found in the category-split between reindeer herders and other Sami created by state policy. Contemporary cleavages in Indigenous politics may, thus, be deeply rooted in nation-building processes.