Headship (School Principal) is a challenging role within a complex and ever-changing policy climate. This article explores the factors which influence headteacher resilience and their mental health. Existing research focuses on teacher resilience but there is a paucity of literature exploring the factors which influence headteacher resilience. This study was conducted in the United Kingdom (UK). Headteachers (n = 16) participated in a semi-structured telephone interview. Participants were asked to categorize their mental health as either good or poor at the time of the interview in relation to the World Health Organization definition of mental health. Participants represented the primary and secondary phases of education and the research included those who were new to the role and those who were more experienced. Male and female participants were represented in the sample. Participants identified a range of factors which influenced their resilience and mental health. These included individual factors, social/relational factors, implementing actions, exposure to challenges, professional learning and systemic factors. Systemic factors included pressures of managing restricted school budgets and external inspections and policy priorities. Participants emphasized the importance of coaching and access to external professional supervision both to support resilience and professional development. Although external professional supervision is common in health and social care professions, it is less common in the education sector, particularly in the UK. A model of teacher resilience has been adapted to address the factors which influence headteacher resilience. In conclusion, the study supports the use of external professional supervision and professional coaching for head teachers to support both their mental health and resilience.