The aim of this study was to test whether resilience and life satisfaction (two traditional protective factors) mediate between COVID-19 related worries and the development of symptoms of depression, anxiety, and stress in adolescents and young adults. Participants involved 392 adolescents and young adults (70.20% female) aged between 12 and 25 years (M = 17.05 years, SD = 3.08). Participants completed the COVID-19 related worries scale, the CD-RISC to analyse resilience, the Satisfaction with Life Scale, and the Depression, Anxiety, and Stress Scales-21 to study emotional symptoms. Descriptive analyses and Pearson correlations were conducted, together with a structural equation modeling testing a mediational model and multigroup invariance. Results show that resilience and life satisfaction play a mediating role in the relation between the COVID-19 related worries and emotional symptoms (depression, anxiety, and stress). This study highlights the role of protective factors on adolescents' and young adults' emotional symptoms during the COVID-19 pandemic.