Historically, empathy has been thought to motivate prosocial behaviour and inhibit aggressive behaviour. Contrary to current assumptions and theoretical support, a meta-analysis revealed a small effect of empathy on aggression among adults (Vachon, Lynam, & Johnson, 2014). The current study sought to determine whether broadening the focus from empathy to include other socially relevant affective characteristics (i.e., callous-unemotional traits) was advantageous in predicting aggressive behaviour. As little is known about the strength of this association among youth, the current study meta-analytically examined 192 unique effect sizes drawn from published and unpublished studies reporting on samples of children and adolescents. Analyses were conducted across general, cognitive, and emotional empathy, as well as callous-unemotional traits, and general, direct, indirect, proactive, and reactive aggression. Significant variability was noted across effect sizes. Consistent with a prior meta-analysis involving adults (Vachon et al., 2014), small to moderate associations were identified between aggression and traditional measures of empathy (i.e., general, emotional, cognitive); these effects ranged from r = -0.06 to -0.26. Among broader measures of emotional style (i.e., callous-unemotional traits), moderate to large effects were found; ranging from r = 0.30 to 0.37. Results suggested that broader affective measures may be more strongly associated with aggression than empathy alone. The results raise questions about the nature of empathy assessment and indicate the utility of targeting multiple emotion-related factors during treatment to effectively reduce aggressive behaviour. In particular, the results underscore of the importance of considering the limited prosocial emotions specifier (perhaps trans-diagnostically given the varied nature of the sample) when considering implications for prognosis and treatment targets.