Researchers have paid limited attention to what makes organizational authority figures decide to treat their employees either justly or unjustly. Drawing from the actor-focused model of justice, as well as the stereotype content model, we argue that employee conscientiousness and agreeableness can impact the extent to which supervisors adhere to normative rules for distributive, procedural, informational, and interpersonal justice, as a result of supervisors' evaluations of their employees' effort and their liking of the employees. Supervisory compliance with justice rules may, in turn, impact the extent to which employees judge themselves to be treated either justly or unjustly. We tested these possibilities in 3 studies. In Study 1, we utilized a meta-analysis to demonstrate positive relationships between employees' conscientiousness, agreeableness, and their justice perceptions. In Study 2, we conducted 3 experiments to test the causal relationship between employee personality and supervisor intentions to comply with justice rules. In Study 3, we conducted an employee-supervisor dyadic field survey to examine the entire mediation model. Results are discussed in terms of the potential roles that both employees and supervisors may play in shaping employees' justice perceptions. (PsycINFO Database Record