It is estimated that between 8% and 50% of beginning teachers in Queensland leave the profession in the first five years. National workforce data indicate that heavy workload is cited as one of the most common reasons for an individual’s choice in leaving. Supporting this, a previous study in Queensland schools identified that approximately 24% of teachers were simultaneously burned-out and engaged. Our pilot data also indicated that in Queensland, 36% of teachers who responded were thinking about leaving the profession, and an additional 25% were actively searching for alternative employment. To address these issues, the Australian Institute for Teaching and School Leadership recommended that all beginning teachers receive mentoring within the first two years of teaching. In 2016, the Queensland Department of Education instituted a mentoring program for all beginning teachers on a permanent or long-term contract. Likewise, many nonstate schools have implemented mentoring programs of their own. Within this context, Griffith University applied for a Queensland Government Education Horizon research grant to investigate the issues of a) beginning teacher wellbeing and turnover intentions and b) the influence of mentoring on wellbeing. This report outlines the results of a mixed methods evaluation of beginning teacher wellbeing and mentoring with rigorous longitudinal multi-source design.