Introduction: Coronavirus disease 2019 (COVID-19) has changed the way families live, interact, and connect with others, resulting in higher levels of stress for many teenagers who struggle with the ongoing uncertainty and disrupted school and family life. The current study examined the psychosocial factors that influence the capacity of adolescents to grow through the stress of the COVID-19 pandemic. Methods: The sample included 404 secondary school students ranging in age from 11 to 18 (M = 14.75, SD = 1.59; 50.2% female, 46.8% male, and 3% non-/other gendered or declined to answer) from an independent high school in Australia. Data were collected from a battery of questionnaires that assessed strength-based parenting (SBP) and the effect of three psychosocial factors (positive reappraisal, emotional processing, and school belonging) on stress-related growth. Results: Structural equation modeling showed that (SBP) was significantly associated with stress-related growth (SRG). Positive reappraisal and emotional processing were also positively and significantly associated with SRG and mediated the effect of SBP on SRG. Moreover, school belonging was positively linked to positive coping, emotional processing, and SRG, as well as mediating the association of SBP with positive reappraisal, emotional processing, and SRG in adolescents during the pandemic. Conclusions: The results show that teenagers can experience SRG during the COVID-19 pandemic, and adolescents adapting by engaging in constructive coping responses such as positive reappraisal and emotional processing is positively related to SRG.