Despite the prevailing discourses on the importance of top management ethical leadership, related theoretical and empirical developments are lacking. Drawing on institutional theory, we propose that top management ethical leadership contributes to organizational outcomes by promoting firm-level ethical and procedural justice climates. This theoretical framework was empirically tested using multi-source data obtained from 4,468 employees of 147 Korean companies from various industries. The firm-level analysis shows that top management ethical leadership significantly predicts ethical climate, which then results in procedural justice climate that fully mediates the effects of top management ethical leadership on two organizational outcomes, namely, firm-level organizational citizenship behavior and firm financial performance. The present study provides a plausible theoretical account and empirical validation of a mechanism through which top management ethical leadership enhances organizational performance.