The present study aimed to explore the professional identity development of English teachers through the lens of the Possible Selves Theory, focusing on the experiences of three distinct groups of educators. An explanatory sequential mixed-method research design was employed using 194 student, novice and experienced English teachers working or studying at various state schools in Turkey. The findings suggested that teacher groups held similar perceptions of their ideals and fears and there was not a significant difference among student, novice and experienced English teacher groups in terms of their possible selves. Additionally, the results revealed that the participants placed a significant emphasis on factors such as professional development, language proficiency, professional competence, personal attributes and recognition in relation to their ideal language teacher selves. The major fears related to their professional identity included language incompetence, inadequate professional development, undesirable personal attributes, undesired professional tendencies and a lack of recognition. The participants also noted various external and internal factors that influenced their possible selves. Based on the findings, a data-driven model on English as a Foreign Language (EFL) Teacher Professional Identity Development (TPID) is proposed to contribute to the existing literature in the field. Context and Implications Rationale for this study Knowing about teachers' current thoughts and their expectations and fears for the future can aid in understanding their identities and potentially transform their future selves, thereby improving the formation of their professional identity. Why the new findings matter The findings of this study are significant as they add to the existing literature on English teachers' professional identity development using the Possible Selves Theory. This framework allows for an examination of teachers' expectations and fears, providing a comprehensive understanding of their professional selves and how these perceptions influence their future actions and goals. This knowledge is critical for designing teacher training programmes and professional development initiatives that support teachers' ongoing professional growth. Implications It is recommended to give increased attention and emphasis to the practical component of student teacher education, specifically the practicum experience, in the curriculum. Opportunities for interaction and collaboration among trainees, mentors and teacher educators should also be provided to enhance the effectiveness of the practicum. Furthermore, to address the concerns of EFL student, novice and experienced teachers about losing their enthusiasm for teaching in the future, comprehensive support mechanisms should be put in place through in-service training and counselling services. Lastly, the Ministry of National Education could establish online and in-person platforms to facilitate interaction and collaboration among teachers.