While the links between the environmental impact of hospitals and population health and system resilience have been acknowledged, the intent to decarbonize has not been translated into actionable programs due to funding, governance, and assessment bottlenecks. To bridge this gap, sustainable finance has been applied within the health sector by tethering capital to verifiable performance and disclosure so that health system environmental targets can be achieved without area compromise, access, quality, and safety. Qualitative, synthesis-based methodologies were used. A concept was developed articulated as “green hospital transformation”; best practices around the world were compared concerning estates, clinical hotspots, and procurement; and the policy-finance architecture of Türkiye, especially public hospitals in Istanbul, was analyzed to find practical implementation avenues. Sustainable-finance frameworks (use-of-proceeds bonds, sustainability-linked instruments, energy-performance contracting) were aligned with taxonomy-compliant activities, measureable indicators, and key performance indicators to allow for portfolio-level deployment. Three key results were produced. Deep metered estates retrofits, clinically supervised substitutions in high-leverage areas (like inhaled anesthesia), and life cycle procurement creates a program logic for rapid, defensible abatement and has system-wide transferable value. Finance instruments operate most effectively as governance tools when eligibility, monitoring, and consequences for under and over-performance are predetermined. Third, measurement and verification conducted routinely without fail are critical to scaling from pilots to portfolios and ensuring credibility with public stakeholders and investors. In Turkey, enabling policies, sovereign level sustainable finance frameworks, and ongoing efficiency and resilience programs have demonstrated criteria of immediate entry points for public providers, while transactional frictions—bundled projects, life cycle costing in procurement, and disclosure capacity—have been characterized as major constraining factors. In the short term, finance-ready clusters have been defined for public hospitals in Istanbul, including standardized retrofit bundles, resilience-aligned on-site generation, and clinically supervised product substitutions. It is concluded that durable progress will be most likely when technical ambition, clinical stewardship, and credible finance are braided together. Adoption of national performance standards, warranted measurement and verification, LCA-anchored procurement, and defined KPI discipline is suggested, together with applied research on equity and metered outcomes. By structuring the research on investable portfolios with evidence-based outcomes, hospitals can be seen as credible stewards of public and planetary resources.