In light of the stagnation in growth of women directors on corporate boards, board diversity advocates and corporate leaders should look to the role implicit gender bias plays in the board nomination process and in challenges women directors face while serving on boards. Relevant stakeholders often overlook how implicit bias barriers prevent women from reaching the boardroom and persist as obstacles once women directors have earned their seats on the board. Incorporating social psychological research on implicit bias and recognized strategies to work around bias, such as objective assessments and guidelines, data analytics, and accountability mechanisms, this Article encourages companies to offer tailored, research-oriented implicit bias trainings to directors and corporate executives to tackle bias concerns. It also suggests modifications to the SEC board diversity disclosure rule to account for the effect of implicit gender bias and advocates collaborative action within companies—including voluntary targets and diversity task forces—to address impediments to women’s advancement in leadership.