As a predominant global innovation paradigm, open innovation constitutes a pivotal means of enhancing firms’ innovation performance. Scholars and practitioners are increasingly concerned about strategies to strengthen open innovation, but previous research has overlooked corporate governance factors. This study empirically investigates the impact of board capital on corporate open innovation using data from Chinese listed firms (1999–2009) within the resource dependence and upper echelons theory framework, employing the fixed effects model for panel data and the hierarchical regression method. Findings reveal that the breadth and depth of board capital positively affect the breadth of open innovation, though not significantly the depth. Additionally, executive equity incentives enhance the relationship between board capital and open innovation breadth. Robustness checks support these findings. Notably, board capital’s impact is more pronounced in large enterprises and high-technology industries. This study offers practical insights for firms to prioritize board capital considerations in fostering open innovation initiatives.