question: BACKGROUND: Although the COVID-19 pandemic has increased the incidence of distress in youth, some children show increased resilience, emphasizing the need to better understand the predictors of distress in youth. OBJECTIVE: This longitudinal study aimed to assess the combined impact of known socio-emotional predictors of stress-related psychopathology, namely anxiety sensitivity, anxiety trait, intolerance to uncertainty, and rumination, on COVID-related distress in healthy youth. METHOD: A total of 92 parent-child dyads that previously participated in a laboratory-based experiment assessing observational fear learning in families between 2017 and 2019 (T0) were recontacted. Of them, 84 children aged between 9 and 14 agreed to participate. They completed online questionnaires in June 2020 (T1), September 2020 (T2), December 2020 (T3), and March 2021 (T4). Participants were free of mental illness at T0 and T1. To create a socio-emotional composite score (SECS), we measured anxiety sensitivity (Childhood Anxiety Sensitivity Index) at T0, trait anxiety (Trait subscale of the State-Trait Anxiety Inventory for Children (STAI-C)), intolerance to uncertainty (Intolerance of Uncertainty Scale for Children), and trait rumination (Children’s Response Style Scale) at T1 and created a weighted z-score. To assess symptoms of anxiety, post-traumatic stress (PTS), and depression in reaction to COVID-19, participants completed the State subscale of the STAI-C, the Children’s Revised Impact of Event Scale, and the Children’s Depression Inventory at T1–T4. Three general linear models were run with sex, age group (9–11 and 12+ years old), and SECS as predictors. RESULTS: Analyses revealed a SECS*Time interaction, with higher SECS predicting elevated anxiety symptoms at T1 and T4, and elevated PTS symptoms at T1 and T2. CONCLUSION: These results suggest that healthy youth endorsing high levels of socio-emotional vulnerability to psychopathology have a higher risk of suffering from anxiety and PTS, but not depressive symptoms, in the year following a major stressor.