The inclusion of morally binding values such as religious—or in a broader sense, spiritual—values fundamentally alter organizational decision-making and ethical behavior. Family firms, being a particularly value-driven type of organization, provide ample room for religious beliefs to affect family, business, and individual decisions. The influence that the owning family is able to exert on value formation and preservation in the family business makes religious family firms an incubator for value-driven and faith-led decision-making and behavior. They represent a particularly rich and relevant context to re-assess the relationship between ethical beliefs, decision-making processes and behaviors in business organizations at the interface between family and professional logics. This Special Issue is dedicated to deepening our understanding of the role religious values and spirituality play in the formation of organizational ethical practices in faith-led family firms and resulting organizational and family-related outcomes. In this editorial, we introduce the 10 papers included in this Special Issue, which investigate the relationship between religion or spirituality and family firm ethical behavior in various geographical, cultural and religious contexts, using a multitude of qualitative and quantitative methodologies. By focusing on the effects of religious or spiritual orientations on both the business and the family, as well as on the values, norms and goals present in the family business system, further research can gain a more nuanced understanding of the relationship between religious and spiritual believes, and sustainable ethical behavior in family firms.