This paper examines the role of green finance in supporting sustainability goals, surveys recent literature and global initiatives, analyses progress and barriers, and identifies gaps and avenues for future research. The study synthesizes secondary sources including policy reports, academic reviews and market data to deliver an integrated picture of how green financial instruments (green bonds, sustainability-linked loans, and blended finance) are mobilising capital for climate mitigation and adaptation. Key findings show strong growth of labeled sustainable debt markets, improving policy frameworks, but persistent challenges in standardisation, data quality, and equitable access to finance. Recommendations include harmonising taxonomies, improving impact reporting, supporting developing economies, and integrating just-transition metrics into finance instruments.