Although numerous individual studies have attempted to link child-parent attachment and prosociality, a systematic picture of that relationship requires a meta-analytic approach that considers different dimensions of prosociality and potential moderators. The current meta-analysis examined 41 studies drawn primarily from North America and Europe and published between 1978 to 2020. Child age ranged from 12 to 53 months at the assessment of child-parent attachment and 12 to 108 months at the assessment of prosociality. Across 35 studies (100 effect sizes, N = 4,611), child-mother attachment security and child prosociality were significantly associated (r = 0.19, 95% CI [0.14, 0.23]). No moderators were identified. Exploratory estimates were also derived for subtypes of child-mother attachment insecurity. Across six studies (eight effect sizes, N = 402), child-father attachment security was significantly associated with prosociality (r = 0.11, 95% CI [0.02, 0.23]). The magnitude of effect sizes did not differ based on parent gender. The discussion considers areas of growth for attachment and prosociality research.