Background The tendency to interpret ambiguity as threat (negative interpretation) has been implicated in cognitive models of anxiety. A significant body of research has examined the association between anxiety and negative interpretation, and reviews suggest there is a robust positive association in adults. However, evidence with children and adolescents has been inconsistent. This study aimed to provide a systematic quantitative assessment of the association between anxiety and negative interpretation in children and adolescents. Method Following systematic searches and screening for eligibility, 345 effects sizes from 77 studies were meta‐analysed. Results Overall a medium positive association was found between anxiety and negative interpretation in children and adolescents (d^ = .62). Two variables significantly moderated this effect. Specifically, the association increased in strength with increasing age and when the content of ambiguous scenarios matched the anxiety subtype under investigation. Conclusions Results extend findings from adult literature by demonstrating an association in children and adolescents with evidence for content specificity in the association. Age effects imply a role for development. Results raise considerations for when and for whom clinical treatments for anxiety focusing on interpretation bias are appropriate. The vast majority of studies included in the review have used correlational designs and there are a limited number of studies with young children. The results should be considered with these limitations in mind.