The current study characterized the impact of the COVID-19 pandemic and stay-at-home orders on adolescents' internalizing symptoms and assessed predictors of adolescents' internalizing symptoms during the pandemic. Seventy-nine adolescents (18 autistic, 61 nonautistic) and their parents who participated in a previous study and were at least 10 years old (M = 13.8, SD = 1.7) were invited to participate in three online follow-up surveys post-stay-at-home order (May through November 2020). Measures of children's anxiety and depressive symptoms, parenting practices, family togetherness, conflict, financial problems, and parental mental health during the pandemic were collected. Nonautistic adolescents experienced a significant decrease in anxiety symptoms across the beginning of the pandemic and a significant increase in depressive symptoms from pre- to post-stay-at-home order. Permissive parenting and financial problems predicted adolescents' depressive symptoms. Parental mental health difficulties and permissive parenting predicted adolescents' anxiety symptoms. Results underscore the need to support parents and youth.