We develop and test a theoretical model of multilevel moderated mediation in which organizational justice serves as an intervening mechanism that explains associations among two dimensions of work stressors (challenges and hindrances) and five dimensions of job performance (task performance, helping, voice, counterproductive behavior, and creativity) over and above the intervening role of strain. We also consider how leadership influences the intervening role of justice in the stressor - job performance relationships by virtue of the effect it has on how stressors are interpreted with regard to fairness. Results of a study of 339 employees and their supervisors provide support for this model across dimensions of performance, albeit unexpectedly, the moderating effect of leadership is contingent on the type of leadership and stressors. Transactional leaders reduce the negative effect of hindrance stressors on job performance because they weaken the negative link between hindrance stressors and justice perceptions. Alternatively, transformational leaders enhance the positive effect of challenge stressors on job performance because they foster a positive link between challenge stressors and justice perceptions. We discuss how this intriguing pattern of moderated mediation could be explained using theory and research on regulatory focus.