The legal standing of Indigenous Peoples in Indonesia’s Administrative Court system remains contested due to the absence of clear procedural standards governing their representation in administrative disputes. This uncertainty has significant implications for Indigenous Peoples’ access to justice, particularly in cases involving state administrative decisions affecting customary rights and territories. Therefore, this article examines how Indonesian courts determine the legal standing of Indigenous Peoples and construct their representation in administrative litigation. This research uses normative juridical research using a court decision analysis approach. It analyzes six disputes involving Indigenous Peoples, comprising ten judicial decisions rendered at the first instance, appellate, and cassation levels. The findings reveal three patterns of Indigenous representation in Administrative Court proceedings: Indigenous communities acting as collective entities, individual members representing collective interests, and customary institutions acting on behalf of the community. Most cases demonstrate the predominance of individual representation based either on deliberative consensus within the community or on existing customary authority structures. The study further identifies a progressive trend in judicial reasoning concerning Indigenous legal standing, including recognition of Indigenous standing without requiring prior formal recognition through regional regulations or decisions of local authorities. In addition, judges generally classify Indigenous Peoples or their representatives as natural persons, reflecting a shift away from rigid formalism and expanding access to administrative justice for Indigenous communities.