AbstractResearch SummaryWhile extant research has studied extensively the consequences of chief executive officer (CEO) succession, we explore the concept of family CEO mentoring (from a departing family CEO to a younger family leader) as a potential driver of post‐succession performance in family firms. Drawing on stewardship theory and using a data set of 1787 Italian firms experiencing a CEO succession over 14 years, we show that family CEO mentoring positively influences post‐succession financial performance. We then argue and empirically confirm that the performance benefit of family CEO mentoring is enhanced by the presence of nonfamily members on the board but is dampened by industry turbulence. We conclude by discussing the implications of our findings for research on CEO mentoring, CEO succession, and family business performance.Managerial SummaryTo thrive across generations, family firms need to navigate the many complexities of chief executive officer (CEO) succession. One way to overcome the challenge is to have a departing family leader who provides mentoring to the younger family leader. Our examination of 1787 Italian family firms that experienced CEO succession in the period 2003–2016 suggests that family CEO mentoring drives better post‐succession firm performance, especially when there is a high presence of nonfamily directors in the boardroom and when the firm operates in low‐volatility industries. This study enhances the understanding of CEO succession by integrating the role of family CEO mentoring as a driver of post‐succession financial performance.