Intolerance of uncertainty and adolescent sleep quality: The mediating role of worry

•The negative effect of intolerance of uncertainty (IU) on adolescent sleep quality is identified.•The relationship between IU and adolescent sleep quality is mediated by worry.•Some means of improving adolescent sleep quality is proposed.

This study explores the relationship between intolerance of uncertainty (IU) and adolescent sleep quality, and tests whether this relationship is mediated by worry. A total of 2286 Chinese adolescents with a mean age of 15.0 years (SD = 1.7) were recruited; they completed questionnaires relating to IU, worry, and sleep quality. The results showed that greater IU was positively correlated with poorer adolescent sleep quality, and this relationship was mediated by worry. The mediating model of worry showed gender and grade invariances. The implications of this study were discussed.