This study examines how green finance reforms affect corporate green innovation, focusing on patent filings in Germany and Singapore between 2010 and 2023. Using patent data from the German Patent and Trademark Office (DPMA) and the Intellectual Property Office of Singapore (IPOS), the analysis applies Difference-in-Differences (DiD) and Triple Difference (TD) econometric models. The findings show that green finance reforms significantly increase green patent applications, with more potent effects observed in Singapore. Larger, privately owned firms benefit the most, while state-owned enterprises respond less to financial incentives. These results suggest that firm characteristics and national policy environments critically shape the effectiveness of green finance initiatives. For policymakers, the study highlights the need for targeted green finance policies considering firm size, ownership structure, and local regulatory contexts. Strengthening green finance can accelerate sustainable innovation and support broader environmental goals, particularly by fostering innovation in agile, private-sector firms. This research offers practical guidance for designing more effective green finance frameworks to achieve national and global sustainability objectives.