This study aims to develop an Ihsan-Based Leadership (IBL) framework and explain how it may strengthen teacher work engagement and contribute to the sustainability of Islamic educational institutions. It adopts a post-positivist perspective and proposes a sequential exploratory mixed-methods design involving qualitative interviews, scale development and validation, and quantitative testing of six propositions using structural equation modeling. As a conceptual study, it derives its findings from theoretical synthesis rather than empirical observations. The analysis identifies four IBL dimensions: muraqabah-based integrity, itqan-driven excellence, rahmah-oriented care, and amanah-based stewardship. These dimensions are expected to generate job resources, including psychological safety, competence, emotional support, autonomy, and transcendental meaning, which may enhance teachers’ vigor, dedication, and absorption. Teacher engagement is further conceptualized as a contributor to four sustainability pillars: academic, human-capital, spiritual-cultural, and financial-operational sustainability. The study concludes that IBL offers an Islamic ethical leadership framework linking inner accountability with professional excellence. Its implications include guiding leadership development and institutional evaluation in practice, while future empirical research must validate the construct, measures, and proposed relationships.