We develop and test a trickle-down model of how authentic leadership at the department level flows down the organizational hierarchy to encourage team leader authentic leadership and consequently, promotes team and individual-level supervisor-directed helping behavior. Analyses of multi-level and multi-source data collected from a total of 487 employees comprising 122 teams, 47 departments, and 4 different working areas of a major public sector organization in Taiwan show that team leaders’ authentic leadership mediates the relationship between departmental authentic leadership and individual-level (...) leader–member exchange. We also found that intra-team trust completely mediates the influence of team authentic leadership on both team helping behavior and individual-level supervisor-directed helping behavior. Finally, the results reveal that self-concordance mediates the influence of team authentic leadership on individual-level supervisor helping behavior as well as the influence of individual-level LMX on individual-level supervisor-directed helping behavior. Theoretical and practical implications of these findings are discussed. (shrink)