Principal leadership plays a crucial role in maintaining educational quality, particularly in rural schools facing limitations in facilities, budget, technology, access to training, and human resources. This study aims to analyze how principal leadership practices are implemented to support teacher professionalism and the quality of the educational process under resource-constrained conditions. The study employed a descriptive qualitative approach using a case study design at SMPN 1 Muara Jawaq, West Kutai Regency, East Kalimantan. Informants were selected through purposive sampling and consisted of one principal, eight teachers, and two educational support staff. Data were collected through in-depth interviews, direct observation, and documentation, then analyzed through data condensation, data presentation, and the drawing and verification of conclusions using triangulation. The results of the study indicate that the principal exercises leadership through policy adjustment, program planning, task allocation, guidance, coordination, motivation, supervision, and evaluation. These practices are related to teacher professionalism, as reflected in discipline, teaching readiness, professional responsibility, and the development of instructional materials, as well as to the quality of the educational process through the regularity of instruction, administration, and school coordination. However, professional development and supervision are not yet fully equitable or sustainable. The study concludes that resource constraints are contextual conditions that shape leadership choices and priorities. Strengthening rural schools therefore requires a combination of leadership capacity building, ongoing supervision, equitable training, and increased resource support.