This study aims to analyze the challenges of ethnic policies within the framework of regional planning and its role in achieving balanced development and population sustainability in Kurdish regions of the Islamic Republic of Iran. Kurdish regions, with their specific cultural, social, and geographical characteristics, have always been considered one of the most sensitive spaces for regional planning in the country. In these regions, the distribution of resources, local participation, and government policy approaches in the field of development and regional justice are strongly influenced by ethnic considerations and centralized decision-making structures. The present study, using a mixed approach (qualitative-quantitative) and using field data, program documents, and policy analysis, examines the interaction of ethnic policies with regional planning processes. The findings show that the weakness in institutionalizing ethnic participation, administrative centralization, and inequality in resource allocation are among the most important factors hindering the balanced development and population sustainability of these regions. The results also indicate that aligning ethnic policies with regional planning can pave the way for strengthening spatial justice, reducing unwanted migration, and increasing social cohesion in Kurdish-populated areas. Finally, a proposed framework for rearranging ethnic policies in the form of regional planning is presented.