As modern constitutions speak in the name of the people, they contribute to constituting the body politic by making potentially contentious claims about its members’ identity, rights, and duties. Focusing on the North and South Korean Constitutions, this article examines the claims about peoplehood articulated in both texts since their concurrent adoption in 1948. The analysis argues that these claims are irreducible to the North and the South competing over two ideologically antagonistic conceptions of the body politic—a rivalry supposedly embodied in and magnified by their constitutions’ use of differentiated terms to designate the people: inmin and kungmin. Instead, these categories should be seen in light of their synchronic commonalities in the North and South Korean Constitutions as well as diachronic transformations throughout the successive versions of each text, revealing that constituting the people has been less a matter of conflict between both Koreas than within each.