In the last several decades, researchers have begun to recognize dysregulated anger as a common and debilitating psychological problem among various populations. Consequently, treatments of anger and aggression have received increasing attention in the literature. Despite considerable progress in this area, the distinction between anger and aggression remains unclear in both theory and practice. For instance, perpetrators of assault or domestic violence are frequently mandated for anger management classes, with the assumption that targeting anger will reduce or eliminate problematic aggressive behaviors; however, the limited literature on this relationship suggests that anger does not always lead to aggression, nor is anger a necessary cause of aggression. Given the context in which most people are referred to anger treatments, we need research demonstrating differential effectiveness of interventions targeting anger and those targeting aggression. The current study reviewed existing meta-analyses of psychosocial treatments of anger and aggression with the aim of comparing effectiveness across outcomes and populations. A comprehensive literature search yielded 13 meta-analyses of treatment studies of anger and eight meta-analyses of treatment studies of aggression published between 1996 and 2016. The results demonstrate that cognitive behavioral treatments represent the overwhelming majority of interventions for anger and aggression in the research literature. Treatments of anger have consistently demonstrated at least small to moderate treatment effectiveness among both non-clinical and psychiatric populations (range of d’s = .31–1.52), whereas aggression treatments have evidenced less reliable effects (range of d’s = .10–1.14). Across studies, there were considerable discrepancies in effect sizes when comparing behavioral outcomes to cognitive ones, demonstrating that despite conceptual overlap between anger and aggression, treatments targeting cognitive constructs (i.e., anger) may not be as effective in reducing aggressive behaviors. While only four of the 13 meta-analyses of anger treatments examined children exclusively, all eight meta-analyses of aggression treatments examined children and adolescents, suggesting that aggression, not anger, is often the primary treatment target and outcome of interest in children. Thus, treatment target often shifts from aggression in childhood to anger in adulthood, but the conceptual basis for this shift has not yet been articulated in the literature. Our findings highlight the importance of clarifying intervention targets in the treatment of anger and aggression, with implications for future research in this area.