Drawing on insights from social learning and social cognitive perspectives and research on the multilevel reality of leadership influences, we developed and tested a multilevel model that examines mechanisms and conditions through which ethical leadership deters work unit- and individual-level ostracism. Based on two field studies using multiple measurement points, we found that at the work unit level of analysis, relational climate partially mediates the negative relationship between ethical leadership and work unit-level ostracism whereas state mindfulness partially mediates the cross-level (...) influence of ethical leadership on individual-level ostracism. Contrary to our hypothesis, we found that the relationship between ethical leadership and relational climate was stronger when work units had a more mechanistic structure, and not when it had an organic work unit structure. Finally, we found that relational climate not only moderates the relationship between state mindfulness and individual-level ostracism, but also moderates the indirect influence of ethical leadership on individual-level ostracism through state mindfulness such that the indirect effect is stronger when relational climate is high as opposed to low. These findings highlight the individual- and work unit-level conditions and mechanisms through which ethical leadership relates to decreased ostracism at work, and thus extends theory and research on ethical leadership and ostracism. (shrink)