This special issue presents the theory of sociocultural models (TSCM) and its applications in diverse areas of psychology, including education, health care, clinical practice, gender relations, and general research. As many theories already exist in the social sciences, some readers may ask: “Why do cross‐cultural, cultural, and indigenous psychologists need another theory?” This question is comprised of two aspects:culture/culturalandtheory/theoretical.Therefore, to answer it, it is important to clarify both issues. The first relates toculturaland its relation topsychological.The second,theory,considers its relation toculturalandpsychological.These issues have long‐range implications for all culture and psychology disciplines as they pose many questions: What role does culture play in the mental functioning of people? How is culture constituted? Is cultural related to social? Does people’s mental functioning exert reciprocal influences on their cultural and social functioning? While working toward answering these questions, researchers quickly determine that more questions arise: What role should theories play in answering these questions? What constitutes theory in culture and psychology disciplines? How should such a theory (or such theories) address the triad of cultural, social, and mental? Consequently, in an effort to provide an overview of the TSCM and to begin to answer these questions, this introduction consists of two parts. The first part addresses the sociocultural turn in modern psychology; this part discusses its implications for research in culture and psychology disciplines. The second segment examines the topic of the theoretical backgrounds of cultural and cross‐cultural research and connects the philosophical paradigms of interpretivism and realism with the theory of sociocultural models. This introduction concludes with a brief overview of the articles included in this issue.