In this paper, we examine whether the presence of a mechanistic structure (i.e., formalization) hinders or facilitates employee thriving at work. In doing so, we examine formalization as an antecedent of employee thriving at work. Specifically, we examine why and when formalization, as an important contextual factor, may facilitate employee thriving at work. We hypothesize that the positive relation between formalization and employees’ thriving at work is mediated by their interpersonal justice perceptions. Further, we hypothesize that ethical leadership moderates the indirect relationship between formalization and employee thriving at work via interpersonal justice. As such, this relationship is stronger in the presence of relatively high (rather than relatively low) levels of ethical leadership. Results from a two‐wave field study provide support for our hypotheses. We also discuss the theoretical and practical implications, limitations, and future research directions for our findings.