Scholars and practitioners in the OB literature nowadays appreciate that emotions and emotional regulation constitute an inseparable part of work life, but the HRM literature has lagged in addressing the emotional dimensions of life at work. In this chapter therefore, beginning with a multi-level perspective taken from the OB literature, we introduce the roles played by emotions and emotional regulation in the workplace and discuss their implications for HRM. We do so by considering five levels of analysis: (1) within-person temporal variations, (2) between persons (individual differences), (3) interpersonal processes; (4) groups and teams, and (5) the organization as a whole. We focus especially on processes of emotional regulation in both self and others, including discussion of emotional labor and emotional intelligence. In the opening sections of the chapter, we discuss the nature of emotions and emotional regulation from an OB perspective by introducing the five-level model, and explaining in particular how emotions and emotional regulation play a role at each of the levels. We then apply these ideas to four major domains of concern to HR managers: (1) recruitment, selection, and socialization; (2) performance management; (3) training and development; and (4) compensation and benefits. In concluding, we stress the interconnectedness of emotions and emotional regulation across the five levels of the model, arguing that emotions and emotional regulation at each level can influence effects at other levels, ultimately culminating in the organization’s affective climate