The Chinese government’s ongoing endeavors to achieve the “low carbon goals” hold immense importance in global emissions reduction. Nonetheless, reducing emissions will inevitably cause economic losses. Therefore, the pursuit of green economic efficiency is regarded as an effective tool to mitigate the economic losses during emission reduction. Synchronously, the realization of green economic efficiency is essential for sustainable development. With the increasing awareness of regional green development, emphasis companies place on environmental, social, and corporate governance (ESG), which contributes to corporate ESG construction, could become a novel advantage in terms of attracting investors. Additionally, it could have a lasting impact on corporate green technological innovation, thereby enhancing the efficiency. Based on the data of A-share listed companies in China from 2009 to 2019, this study analyzes the effect of corporate ESG construction on the efficiency of regional green economy as well as its mechanism. The research findings demonstrate a significant positive impact of corporate ESG construction on the efficiency of regional green economies. Specifically, each unit improvement in corporate ESG construction is associated with an approximate 0.7% increase in the efficiency of the regional green economy. The conclusion can be drawn after robustness testing. Notably, the effect of corporate ESG construction is more pronounced for companies located in the eastern region, state-owned enterprises, and high-polluting industries. In terms of the underlying mechanism, corporate ESG construction facilitates regional green economic efficiency by fostering corporate green technological innovation. Furthermore, it is observed that environmental regulations have a negative moderating influence on corporate ESG construction, which in turn affects regional green economic efficiency. When examining the decomposed variables of regional green economic efficiency, the impact of corporate ESG construction on regional green scale efficiency is found to align with its overall effect on regional green economic efficiency. This study contributes to the existing research on corporate ESG construction and regional green economic efficiency, offering valuable insights to guide companies in enhancing both aspects. Building upon the conclusions drawn, we will provide policy recommendations from the perspectives of the company itself, corporate investors, and the government. These recommendations aim to facilitate improvements in corporate ESG construction and foster the enhancement of regional green economic efficiency.