India’s natural gas sector is pivotal to energy security and economic growth, yet faces increasing pressure to align with Environmental, Social, and Governance (ESG) principles amid the nation’s low-carbon transition. This study develops and evaluates subsector-specific ESG materiality frameworks, integrating perspectives from internal stakeholders (e.g., employees with experience or knowledge of sustainability/ESG and at different hierarchical levels) and external stakeholders (e.g., regulators, non-governmental organizations, suppliers, and customers) through surveys and expert interviews. Materiality matrices from gas sector segments (i.e., upstream, midstream, downstream, and integrated operations) highlight greenhouse gas emissions, water management, and stakeholder engagement as priorities, with sectoral differences: upstream activities focus on emissions, whereas downstream operations emphasize energy efficiency—identified using Kruskal–Wallis tests (e.g., p = 0.014 for greenhouse gas emissions). Correlation analyses revealed strong links, such as between emissions and low-carbon strategies (τ = 0.58–0.65), guiding materiality prioritization. Alignment with global standards (e.g., Global Reporting Initiative, Sustainability Accounting Standards Board, International Petroleum Industry Environmental Conservation Association) and India’s Business Responsibility and Sustainability Reporting framework was robust for environmental factors but weak in biodiversity (16.7%), supply chain sustainability (25%), and Sustainable Development Goals 5 (gender equality) and 14 (life below water). These gaps highlight opportunities for tailored ESG strategies. Recommendations include collaborative platforms, advanced analytics, and regulatory incentives to enhance compliance and address stakeholder expectations. The framework provides a strategic guide for sustainable practices, strengthening the sector’s resilience and supporting India’s sustainable energy future.