This study investigated the potential benefits of integrating Multiple Intelligences (MI)-based approaches into teacher training programs for enhancing English language teaching (EFL) in Iran. Twenty in-service EFL teachers participated in a quasi-experimental pre-test post-test control group design. The experimental group received an 8-week training program focused on MI theory and its application in EFL practices. The control group received training on the influence of psychological factors on student learning. Both groups exhibited significant improvements in academic optimism and psychological wellbeing after the training program. However, the experimental group demonstrated larger effect sizes for both measures, suggesting a potentially stronger positive impact of the MI-based training. One-way analyses of covariance (ANCOVA) controlling for pre-test scores further confirmed a significant effect of the intervention program on both academic optimism and psychological wellbeing. These findings highlightthe potential value of incorporating MI principles into EFL teacher training programs to foster not only teacher development but also their overall wellbeing
