Purpose: The current study seeks to explore the links between principal self-efficacy, openness to change, well-being, and transformational leadership. Specifically, we tested a mediated-effects model where principal self-efficacy and openness to change were treated as independent variables, well-being as mediator, and transformational leadership as dependent variable. Design/methodology/approach: Survey data were collected from 351 principals employed in Turkish schools and analysed using confirmatory factor analysis and structural equation modelling. Findings: The results suggested the direct empirical relationship of principal self-efficacy and openness to change with transformational leadership, and indirect through professional well-being. Originality/value: Our study enriched our understanding of school leadership by elucidating the potential mechanisms that underpin the implementation of transformational leadership practices.