Online learning has grown in popularity over the last few years. Understanding what factors and how they contribute to students' e-learning engagement is crucial for the success of online education. Based on the ecological system theory, this study aims to examine the association between perceived social support and e-learning engagement among Chinese college students and explore whether growth mindset and subjective well-being mediated this association. A survey was conducted among 605 college students in China. The results showed that perceived social support is positively and significantly associated with e-learning engagement and that growth mindset and subjective well-being play independent and joint mediating roles in the link between the two constructs. Our findings highlight the importance of the interaction between perceived social support, growth mindset, and subjective well-being in e-learning engagement among college students. This study contributes to the theoretical and practical understanding of the e-learning ecosystem in college students.