Although the relationships between managerial practices and work-related outcomes are contingent on leadership behaviors, little scholarly attention has been paid to how leadership styles shape the impact of distributive justice and goal clarity on employees’ organizational citizenship behavior (OCB) in the field of organizational behavior and management. In this context, this study examines the direct effects of distributive justice and goal clarity on OCB based on two motivation theories, equity theory and goal-setting theory, as well as the moderating role of transactional and transformational leadership in the relationships based on social exchange theory. Using survey data from a sample of 4133 public employees drawn from Korean central and local governments and ordinary least square regression models, we found that distributive justice is negatively related to OCB, whereas goal clarity is positively related to OCB. Further analysis shows that while transactional leadership weakens the negative relationship between distributive justice and OCB, transformational leadership strengthens the positive relationship between goal clarity and OCB. Consequently, our study provides meaningful implications for public managers and organizations that should be considered in order to implement effective managerial practices based on the fitness between employee motivation processes and leadership styles to encourage employees to exhibit OCB. This will enhance organizational performance and sustainability