Drawing on social learning and self-determination theories, this study investigates the mediating effects of controlled motivation for knowledge sharing and moral identity in the relationship between ethical leadership and employee knowledge sharing. We conducted a field study with 337 full-time employees to test our hypotheses. Results supported the mediating effects of both controlled motivation and moral identity in accounting for the relationship between ethical leadership and employee knowledge sharing. Our study is among the first to examine whether and why ethical leadership predicts employee knowledge sharing. Theoretical and practical implications are discussed.