Objective To conduct a meta-analysis of social competence in children with a chronic illness. Methods The meta-analysis included 57 studies comparing levels of social competence in children with chronic illness to those of children without chronic illness. A random effects model was used to calculate overall effect, subgroup, and meta-regression analyses. Results Overall, the meta-analysis calculated 90 unique outcomes, producing a summary standardized mean difference of d = –0.44, 95% confidence interval (95% CI) –0.52 to –0.36 indicating a medium overall effect for decrease social competence. Chronic illness, measure, and informant moderated social competence outcomes. Conclusions The impact of chronic illness on youth varied by individual child factors (e.g., gender, chronic illness type) and by measurement features such as informant and measure type. The current study demonstrates a need for further research of the assessment of social competence and has implications for the development of social skills programs for children with chronic illness.