A social identity theory of leadership is proposed, viewing leadership as a group process influenced by social categorization and prototype-based depersonalization. Group identification, as self-categorization, creates an intragroup prototypicality gradient, where the most prototypical member appears to have influence. This appearance becomes reality through depersonalized social attraction, leading followers to agree with the leader. Consensual social attraction creates a status-based differentiation between leaders and followers. A fundamental attribution process also constructs a charismatic leadership personality, further empowering the leader. Empirical support for the theory is reviewed, with implications for intergroup dynamics, uncertainty reduction, power, and prototype-based leadership pitfalls. Leadership research has historically been less emphasized in social psychology, but recent developments have reintroduced it through social identity perspectives. Leadership is viewed as a dynamic product of leader-follower interactions, with followers attributing charisma and power to leaders. Transactional leadership focuses on transformational and charismatic leadership, emphasizing proactive, innovative, and inspiring leaders. Social cognition has extended implicit leadership theory into leader categorization theory, where preconceptions about leadership behavior influence perceptions. Social identity theory and self-categorization theory are central to understanding leadership. Social identity involves group membership and self-enhancement motives, while self-categorization involves perceiving oneself in terms of group prototypes. Depersonalization processes lead to stereotypical perceptions of others and group behaviors. Prototypes are context-sensitive, influencing perceptions and behaviors. Social attraction, based on perceived prototypicality, enhances leader influence and status. Uncertainty reduction motives also drive leadership, as people seek to reduce subjective uncertainty through group membership. Salience of group membership influences leadership perceptions, with prototypicality becoming a key basis for leadership. Social identity processes differentiate groups, with prototypicality affecting leadership effectiveness. Intragroup processes involve structural differentiation into leaders and followers. Leadership emerges from prototypicality, social attraction, and attribution processes. Empirical studies support the theory, showing that prototypicality increases leadership effectiveness and that social attraction enhances leader status. The theory has implications for intergroup relations, power dynamics, and leadership effectiveness. Future research should explore how social identity processes influence leadership in various contexts. The theory provides a framework for understanding leadership as a group process, emphasizing the role of social identity and prototypicality in shaping leadership perceptions and behaviors.A social identity theory of leadership is proposed, viewing leadership as a group process influenced by social categorization and prototype-based depersonalization. Group identification, as self-categorization, creates an intragroup prototypicality gradient, where the most prototypical member appears to have influence. This appearance becomes reality through depersonalized social attraction, leading followers to agree with the leader. Consensual social attraction creates a status-based differentiation between leaders and followers. A fundamental attribution process also constructs a charismatic leadership personality, further empowering the leader. Empirical support for the theory is reviewed, with implications for intergroup dynamics, uncertainty reduction, power, and prototype-based leadership pitfalls. Leadership research has historically been less emphasized in social psychology, but recent developments have reintroduced it through social identity perspectives. Leadership is viewed as a dynamic product of leader-follower interactions, with followers attributing charisma and power to leaders. Transactional leadership focuses on transformational and charismatic leadership, emphasizing proactive, innovative, and inspiring leaders. Social cognition has extended implicit leadership theory into leader categorization theory, where preconceptions about leadership behavior influence perceptions. Social identity theory and self-categorization theory are central to understanding leadership. Social identity involves group membership and self-enhancement motives, while self-categorization involves perceiving oneself in terms of group prototypes. Depersonalization processes lead to stereotypical perceptions of others and group behaviors. Prototypes are context-sensitive, influencing perceptions and behaviors. Social attraction, based on perceived prototypicality, enhances leader influence and status. Uncertainty reduction motives also drive leadership, as people seek to reduce subjective uncertainty through group membership. Salience of group membership influences leadership perceptions, with prototypicality becoming a key basis for leadership. Social identity processes differentiate groups, with prototypicality affecting leadership effectiveness. Intragroup processes involve structural differentiation into leaders and followers. Leadership emerges from prototypicality, social attraction, and attribution processes. Empirical studies support the theory, showing that prototypicality increases leadership effectiveness and that social attraction enhances leader status. The theory has implications for intergroup relations, power dynamics, and leadership effectiveness. Future research should explore how social identity processes influence leadership in various contexts. The theory provides a framework for understanding leadership as a group process, emphasizing the role of social identity and prototypicality in shaping leadership perceptions and behaviors.