Green finance has appeared as an important mechanism in position financial flows with sustainable development objectives. In contrast to earlier studies, primary goal of the study is to observe the effect of green finance on social, environmental, and economic sustainability in high- and upper-middle-income nations. Panel data is used from 2015 to 2024 to use the CS-ARDL model and cointegration to observe the effect of green finance on sustainable development. Four indices, i.e., green finance index, environmental sustainability index, social sustainability index, and economic sustainability index, are constructed. We used different econometric techniques to account for the influence of green finance on environmental sustainability, economic sustainability, and social sustainability. Environmentally, green finance loans and bonds significantly decline environmental degradation and increase the implementation of sustainable energy practices. Economically, green finance increases growth by encouraging environmentally compliant investment promotion and sound regulatory government while lessening the negative impact of inflation and income inequality. Socially, it boosts inclusion and equity through corporate responsibility, job creation, and targeted investment in underserved communities. The findings show that foreign finance is a significant tool for promoting social well-being, supporting economic growth environmentally, and achieving sustainable development. The study results suggest some policies for specific economies separately and collectively.