The article examines the theoretical foundations of professional identity formation among future primary school teachers. Based on scholarly literature analysis, professional identity is defined as an integrative personal formation characterized by conscious acceptance of pedagogical values, professional norms, and behavioral models. The paper presents a comparative analysis of three key theoretical approaches to studying this phenomenon: Personal Interpretative Framework (PIF) theory, Korthagen's "Onion Model" concept of professional development, and Day & Kington's theory of professional, situational, and personal identity. Through comparative analysis, common conceptual provisions and specific features of the examined theoretical constructs are identified in the context of primary education teacher preparation. The significance of this work lies in the potential application of the identified theoretical principles in developing methodologies for forming professional identity of future primary school teachers during their professional training.