General Background: Development and environmental sustainability are interdependent components of national progress. Specific Background: Environmentally inclusive development emphasizes the wise, planned, and sustainable use of resources to enhance quality of life. Knowledge Gap: However, the interplay between income inequality, inclusive economic development, and environmental quality remains underexplored in the Indonesian context. Aim: This study investigates the dynamic relationship between income inequality, inclusive development, and environmental quality across Indonesia’s 34 provinces. Results: The findings reveal a bidirectional negative relationship: inclusive economic development significantly reduces income inequality, while lower income inequality promotes more inclusive development. Novelty: This research provides empirical evidence on the reciprocal nature of inequality and inclusivity within a sustainability framework, contributing to a deeper understanding of socio-environmental policy integration in developing economies. Implications: The results underscore the importance of implementing inclusive and environmentally aware development strategies as a means to address inequality and enhance long-term sustainability outcomes. Highlights: Highlights the reciprocal relationship between inequality and inclusive development. Provides empirical evidence from 34 Indonesian provinces. Emphasizes the role of sustainability in equitable economic growth. Keywords: Income Inequality, Inclusive Development, Environmental Quality, Sustainable Development