Based on the job demands–resources model, this study considers how employees’ perceptions of organizational politics might reduce their engagement in organizational citizenship behavior. It also considers the moderating role of two contextual resources and one personal resource (i.e., supervisor transformational leadership, knowledge sharing with peers, and resilience) and argues that they buffer the negative relationship between perceptions of organizational politics and organizational citizenship behavior. Data from a Mexican-based manufacturing organization reveal that perceptions of organizational politics reduce organizational citizenship behavior, but the effect is weaker with higher levels of transformational leadership, knowledge sharing, and resilience. The buffering role of resilience is particularly strong when transformational leadership is low, thus suggesting a three-way interaction among perceptions of organizational politics, resilience, and transformational leadership. These findings indicate that organizations marked by strongly politicized internal environments can counter the resulting stress by developing adequate contextual and personal resources within their ranks.