This systematic review of 285 servant leadership articles from 1998 to 2018 highlights the need for a comprehensive and integrated understanding of servant leadership. The review identifies four key areas for advancement: conceptual clarity, measurement rigor, theoretical and nomological network mapping, and future research directions. Servant leadership is defined as an other-oriented approach focused on follower development, emphasizing psychological needs, ethical values, and spiritual growth. It differs from transformational, ethical, and authentic leadership in its focus on follower development as an end in itself, rather than a means to organizational goals. The review evaluates 16 servant leadership measures, finding that only seven have sufficient psychometric validity. Three measures—SL-7, SLBS-6, and SLS—are recommended for future research due to their rigorous construction and validation. The review also highlights the need for more experimental research to address endogeneity and causal relationships, as well as the importance of considering non-traditional leadership contexts. Empirical studies show that servant leadership positively influences follower outcomes such as organizational citizenship behavior (OCB), job satisfaction, and performance. The review maps the nomological network of servant leadership, identifying antecedents like leader personality, organizational culture, and situational factors, as well as outcomes such as follower development, organizational commitment, and team performance. The review also notes the need for more research on the effects of servant leadership in diverse contexts, including non-traditional leadership structures and cross-cultural settings. The review concludes that servant leadership is a distinct leadership approach with potential to address modern workplace challenges while fulfilling basic human needs. Future research should focus on theoretical and empirical advancements to further develop and validate servant leadership theories. The review emphasizes the importance of using robust measurement tools, experimental designs, and cross-cultural studies to enhance the understanding and application of servant leadership.This systematic review of 285 servant leadership articles from 1998 to 2018 highlights the need for a comprehensive and integrated understanding of servant leadership. The review identifies four key areas for advancement: conceptual clarity, measurement rigor, theoretical and nomological network mapping, and future research directions. Servant leadership is defined as an other-oriented approach focused on follower development, emphasizing psychological needs, ethical values, and spiritual growth. It differs from transformational, ethical, and authentic leadership in its focus on follower development as an end in itself, rather than a means to organizational goals. The review evaluates 16 servant leadership measures, finding that only seven have sufficient psychometric validity. Three measures—SL-7, SLBS-6, and SLS—are recommended for future research due to their rigorous construction and validation. The review also highlights the need for more experimental research to address endogeneity and causal relationships, as well as the importance of considering non-traditional leadership contexts. Empirical studies show that servant leadership positively influences follower outcomes such as organizational citizenship behavior (OCB), job satisfaction, and performance. The review maps the nomological network of servant leadership, identifying antecedents like leader personality, organizational culture, and situational factors, as well as outcomes such as follower development, organizational commitment, and team performance. The review also notes the need for more research on the effects of servant leadership in diverse contexts, including non-traditional leadership structures and cross-cultural settings. The review concludes that servant leadership is a distinct leadership approach with potential to address modern workplace challenges while fulfilling basic human needs. Future research should focus on theoretical and empirical advancements to further develop and validate servant leadership theories. The review emphasizes the importance of using robust measurement tools, experimental designs, and cross-cultural studies to enhance the understanding and application of servant leadership.