A large body of literature examines parental interpretations of their child’s autism diagnosis. However, research examining intersections between parental disclosure of their child’s autism diagnosis to their child and their child’s identity development is lacking. The primary aim of this study was to analyze if parental decisions to disclose/withhold their child’s autism diagnosis influence adolescents’ perceptions of autism and identity development. Adolescent participants (n = 19) and their mothers, recruited from an informal educational program, completed in-person interviews and online questionnaires, respectively. Adolescents were told about their autism diagnosis in varying ways. Adolescents whose parents voluntarily disclosed their autism diagnosis to them described autism and themselves more positively than adolescents who did not experience voluntary disclosure. Although parents and teens showed similarities on a group level when defining autism, parents and children expressed diverse themes in their definitions of autism. Findings suggest that parents can help their children develop neurodiversity-aligned perspectives about autism by mindfully discussing autism with them early in their development.