This study examines the findings and implications of research on trust in leadership over the past 40 years. It provides estimates of the primary relationships between trust in leadership and key outcomes, antecedents, and correlates (k = 106). The study explores how specifying the construct with alternative leadership referents (direct leaders vs. organizational leadership) and definitions (types of trust) results in systematically different relationships between trust in leadership and outcomes and antecedents. Direct leaders (e.g., supervisors) appear to be a particularly important referent of trust. A theoretical framework is offered to provide parsimony to the expansive literature and to clarify the different perspectives on the construct of trust in leadership and its operation. Trust in leadership has been recognized by researchers for at least four decades, with early exploration in books and empirical articles. Over time, trust has been an important concept in applied psychology and related disciplines. Trust is a key concept in several leadership theories, including transformational and charismatic leadership, and is an element of leader-member exchange theory and the consideration dimension of leader behavior. The importance of trust in leadership has also been emphasized in numerous other literatures across multiple disciplines. Researchers have demonstrated significant and growing interest in the concept, but several key issues have been overlooked. First, there has been no attempt to cumulate and assess the empirical research on trust in leadership that is spread across several decades and numerous literatures. Second, a diversity in construct focus has arisen in the literature. In examining the relationship of trust with other constructs, researchers have specified the construct with different leadership referents and with a focus on different operational definitions of trust. Third, scholars from different literatures have used and adapted the concept, leading to different theoretical perspectives. The study reports a meta-analysis that quantitatively summarizes and evaluates the primary relationships between trust in leadership and 23 constructs. The study explores whether choosing to focus on one particular operational definition of trust versus another may result in different findings. The study also explores whether trust in leadership is related to different outcomes and antecedents depending on the referent of leadership or the definition of trust. The study finds that trust in leadership is positively related to job performance, organizational citizenship behaviors (OCBs), job satisfaction, organizational commitment, goal commitment, and belief in information, and negatively related to intention to quit. Trust is also linked to attitudinal outcomes, particularly organizational commitment and job satisfaction. Trust is positively related to transformational leadership, perceived organizational support, interactional justice, transactional leadership, procedural justice, participative decision making (PDM), distributive justice, propensity to trust, and length of relationship, and negatively related to unmet expectations. The study also finds that trust in leadership is positively related to satisfaction with leader and LMX. The study explores the implications of specifying the construct in different ways and provides theoretical parsimony to the literature base. These issues are important to address from a theoretical standpoint because they limit the ability of scholarsThis study examines the findings and implications of research on trust in leadership over the past 40 years. It provides estimates of the primary relationships between trust in leadership and key outcomes, antecedents, and correlates (k = 106). The study explores how specifying the construct with alternative leadership referents (direct leaders vs. organizational leadership) and definitions (types of trust) results in systematically different relationships between trust in leadership and outcomes and antecedents. Direct leaders (e.g., supervisors) appear to be a particularly important referent of trust. A theoretical framework is offered to provide parsimony to the expansive literature and to clarify the different perspectives on the construct of trust in leadership and its operation. Trust in leadership has been recognized by researchers for at least four decades, with early exploration in books and empirical articles. Over time, trust has been an important concept in applied psychology and related disciplines. Trust is a key concept in several leadership theories, including transformational and charismatic leadership, and is an element of leader-member exchange theory and the consideration dimension of leader behavior. The importance of trust in leadership has also been emphasized in numerous other literatures across multiple disciplines. Researchers have demonstrated significant and growing interest in the concept, but several key issues have been overlooked. First, there has been no attempt to cumulate and assess the empirical research on trust in leadership that is spread across several decades and numerous literatures. Second, a diversity in construct focus has arisen in the literature. In examining the relationship of trust with other constructs, researchers have specified the construct with different leadership referents and with a focus on different operational definitions of trust. Third, scholars from different literatures have used and adapted the concept, leading to different theoretical perspectives. The study reports a meta-analysis that quantitatively summarizes and evaluates the primary relationships between trust in leadership and 23 constructs. The study explores whether choosing to focus on one particular operational definition of trust versus another may result in different findings. The study also explores whether trust in leadership is related to different outcomes and antecedents depending on the referent of leadership or the definition of trust. The study finds that trust in leadership is positively related to job performance, organizational citizenship behaviors (OCBs), job satisfaction, organizational commitment, goal commitment, and belief in information, and negatively related to intention to quit. Trust is also linked to attitudinal outcomes, particularly organizational commitment and job satisfaction. Trust is positively related to transformational leadership, perceived organizational support, interactional justice, transactional leadership, procedural justice, participative decision making (PDM), distributive justice, propensity to trust, and length of relationship, and negatively related to unmet expectations. The study also finds that trust in leadership is positively related to satisfaction with leader and LMX. The study explores the implications of specifying the construct in different ways and provides theoretical parsimony to the literature base. These issues are important to address from a theoretical standpoint because they limit the ability of scholars