This article examines interpretations of the free democratic basic order (FDBO) in South Korea regarding the task of unification. The interpretation of the FDBO is a central issue in discussions around unification, because actors are bound by it in a fundamental sense, and also because conceptually it has the potential for bringing together the two Koreas in a peaceful and democratic way. The article first investigates the historical context in which the specific introduction and change of the FDBO in the constitution and other closely related legal norms occurred. Secondly, the article examines the diverging definitions of the contents and application of the FDBO with respect to unification by reviewing related Constitutional Court decisions as well as authoritative legal scholarship that comments on the matter.