Background: Diabetes self-management is suboptimal in adolescents with type 1 diabetes (T1D), including those in China. Objectives: The aim of the study was to investigate the impact of parent–child relationship quality on diabetes self-management. Data were collected by a self-report survey among 122 Chinese adolescents from April to July 2017. The data were analyzed using a one-way analysis of variance, descriptive analyses, correlation analyses, and mediation analyses.