The rapid expansion of environmental, social, and governance (ESG) reporting has reshaped sustainability practices across global financial markets. However, prevailing ESG frameworks are largely grounded in Western institutional and ethical paradigms, potentially limiting their relevance for Islamic banking institutions, which operate under distinct Sharia-based principles emphasizing ethical conduct, social justice, and risk sharing. This paper proposes a conceptual shift from ESG to ESGI by explicitly integrating Islamic ethical and governance dimensions into sustainability disclosure frameworks. Drawing upon stakeholder theory, legitimacy theory, institutional theory, and ethical decision-making theory, the study develops an integrated conceptual framework to explain how ESGI disclosures may influence financial performance in Islamic banks. Through a focused synthesis of prior empirical and theoretical research, the paper identifies key mechanisms, including enhanced stakeholder trust, reputational capital, regulatory legitimacy, and improved risk management. The proposed framework highlights the moderating roles of Sharia governance quality and institutional environments in shaping ESGI performance outcomes. By advancing a theoretically grounded ESGI model, this study contributes to sustainable finance literature and offers a foundation for future empirical research. Also, the framework provides actionable insights for regulators, standard-setters, and Islamic bank managers seeking to align sustainability strategies with Islamic ethical principles.