<p>Green financial technology (fintech) focuses on achieving sustainable development goals. The Ant Forest application is a typical example that reflects the characteristics of green fintech, serving as a focal point for investigation in this study. Environmental concerns and green trust are important factors in promoting the user acceptance and adoption of green services. As green fintech has green and technological features, however, the joint effects among environmental concerns and green trust and the technology adoption perspective on users’ sustainable use of green fintech (i.e., Ant Forest) remain unknown. To address this research gap, the expectation-confirmation model (ECM) is applied in this paper by integrating environmental concerns and green trust to construct a research model to investigate users’ continuous willingness to use green fintech. We employed a survey research method by collecting 653 responses to examine the model. A partial least squares structural equation modeling (PLS-SEM) approach was adopted for statistical examination. The results show that environmental concerns can improve green trust and that green trust can improve user satisfaction through confirmation and perceived usefulness, thus enhancing users’ willingness to continuously use green fintech. This paper provides theoretical contributions by extending two green antecedents (i.e., environmental concerns and green trust) to the ECM to further understand user decisions to continuously use green fintech. The findings also hold significant practical implications for green fintech vendors, especially in terms of designing fintech solutions and collaborating with environmental agencies to promote continuous public use of green fintech.</p>