Abstract. Over two decades of research has indicated that group affect is an important factor that shapes group processes and outcomes. We review and synthesize research on group affect, encompassing trait affect, moods, and emotions at a collective level in purposive teams. We begin by defining group affect and examining four major types of collective affective constructs: (a) convergence in group affect; (b) affective diversity, that is, divergence in group affect; (c) emotional culture; and (d) group affect as a dynamic process that changes over time. We describe the nomological network of group affect, examining both its group-level antecedents and group-level consequences. Antecedents include group leadership, group member attributes, and interactions between and relationships among group members. Consequences of group affect include attitudes about the group and group-level cooperation and conflict, creativity, decision making, and performance. We close by discussing current research knowns, research needs, and what lies on the conceptual and methodological frontiers of this domain.