The banking industry is placing increasing emphasis on green finance to address climate change, support sustainable development, and align with environmental, social, and governance (ESG) goals, as well as sustainable investments to fund environmentally friendly projects. In an era of growing regulatory pressure and rising demand for sustainability from investors and stakeholders, green finance has become a vital tool for banks to enhance operational efficiency. It can reduce operational costs by financing energy-saving projects, improve asset quality by funding low-risk sustainable projects, and even attract capital from environmentally responsible capital markets. Additionally, green finance helps improve risk management frameworks by financing projects that align with long-term sustainable development objectives. This paper explores the relationship between green finance and the operational efficiency of three major banks—RHB Bank, Industrial and Commercial Bank of China (ICBC), and Deutsche Bank. The article focuses on analyzing how these banks integrate green finance into their strategies and the overall impact of these initiatives on operational performance, primarily cost reduction.