This dissertation explored the experiences of career change teachers (CCTs) in Irish primary and post-primary schools. Their motivations for changing career, expectations of teaching as a career and the challenges encountered during their career change were examined. The theme of identity and its role in CCTs’ motivations to change career and subsequently leave the profession was central to this study. Stryker’s (1968) theory of identity, in particular, the multiple identities which a person holds, formed the basis for this study’s theoretical framework, complemented by Holland’s (1997) theory of vocational choice and Lave and Wenger’s (1991) theory of situated learning. This research used a convergent parallel mixed methods design, with a sample of 112 participants. Data was gathered through the use of an online survey, completed by 107 participants and fifteen semi-structured interviews, ten of whom had also completed the online survey. The quantitative data from the online questionnaire provided descriptive statistics of the backgrounds of participants and an overview of their routes into teaching and experience of changing career. The qualitative data from the questionnaire and interviews were coded using thematic analysis and provided a deeper insight into CCTs’ experiences of changing career to teaching, the reasons for their attrition and the role of professional identity through all stages. The main motivations identified by CCTs for changing career included a long-held desire to become a teacher, the influence of family members who were also teachers, crucial life events, positive prior teaching and learning experiences, loss of employment and interest in their previous job and other more extrinsic motivations. Developing a new professional identity as a CCT was influenced by personal factors and relationships with colleagues and pupils. The reasons for attrition provided by CCTs were lack of job security, the school context, professional registration issues and a lack of teacher identity. Job security and a positive school environment which acknowledges and values the backgrounds, experiences and skills of CCTs each support the development of a CCTs’ teacher identity and contribute to their retention in the profession. This research study provides a deeper understanding of the motivations, skills and experience that CCTs bring to teaching and the factors that contribute to their attrition. This knowledge will assist in the recruitment of this diverse cohort of teachers and alleviate the teacher shortage in Ireland, particularly at post-primary level.