<p>This study investigates the impact of cultural intelligence (CQ) on the well-being of international Chinese language teachers and the underlying mechanisms. An explanatory sequential mixed-methods study was employed. In the first phase, questionnaire data from 187 teachers were analyzed using structural equation modeling to examine the direct effects of CQ on well-being and mediating pathways. In the second phase, semi-structured interviews with eight teachers were thematically analyzed to further explore and contextualize the key pathways identified in the quantitative model. The findings reveal that CQ positively influences these teachers’ well-being (TWB) through one direct pathway and three indirect pathways: (1) CQ has a significant direct effect on TWB: “CQ → TWB”; (2) social-emotional competence (SEC) and colleague relationships (CR) play significant chain mediating roles, forming three indirect pathways: “CQ → SEC → TWB”, “CQ → CR → TWB”, and “CQ → SEC → CR → TWB”. This study is the first to validate this chained mediation mechanism among international Chinese language teachers, thereby enriching the intersectional perspectives of cross-cultural adaptation theory and positive psychology. Furthermore, it proposes a three-stage intervention model—encompassing CQ training, SEC development, and CR enhancement—to inform practical strategies for teacher selection, pre-service training, organizational management, and instructional support in international Chinese education.</p>