This study examines the influence of women’s board representation on the proportion of women senior managers in the United Kingdom (UK) from 1999 to 2019. We take a multi-theoretic approach, drawing on the trickle-down effect, critical mass theory, and agency theory, to explore several aspects of this topic. We find that more women on boards is associated with more women in senior management as suggested by the trickle-down perspective. We also find support for a critical mass effect; while one or (...) two women on a board is beneficial for advancing women into senior management, three or more women directors is more advantageous. Consistent with agency theory expectations, the relationship between women on boards and senior management gender diversity is driven almost entirely by women in non-executive, rather than executive, board positions, presumably as a result of the relative independence non-executive directors have compared to their executive director counterparts. Our study suggests that increasing women’s board appointments is a potential solution to the underrepresentation of women senior managers and may assist in building a pipeline for future CEO and board appointments. (shrink)