This chapter aims to provide a wide overview of the board of directors in family firms, showing the progress in the academic literature over the last three decades. The chapter starts with a discussion of the roles attributed to boards of directors in family businesses. It also offers an overview of the so-called input–output model that has dominated the last few decades of research, and provides reflections on board composition; the relationship between board independence and performance; the association between composition and strategic outcomes; family ties and duality of CEOs; combined effects of CEO characteristics; and the relationship between board of directors/CEO characteristics and non-financial outputs. The chapter also integrates behavioral aspects of board functioning, opening the “black box” of the relationship between structural characteristics (input) and firm outcomes (output). Finally, it completes the input–process–output model with another conceptual element, the antecedents of boards of directors.