Evidence suggests that problematic use of gaming, the internet, and social media among adolescents is on the rise, affecting multiple psycho-emotional domains . However, research providing a comprehensive and triangulated stakeholder perspective of perceived harms is lacking . How are adolescent online harms experienced and conceptualized by students, parents, and teachers? The present study comprised part of a qualitative needs assessment investigation with the use of focus groups and individual interviews among key stakeholder groups assessing perceived impacts with a focus on the negative consequences and perceived harms . The study ’ s sample consisted of students (N = 42, Mage = 13.5, SD = 2.3), parents (N = 9, Mage = 37, SD = 5.6) and teachers (N = 9, Mage = 34, SD = 4.9) from the UK . Data were analysed with thematic analysis . Findings focused primarily on social media use impacts and indicated that processes underlying impacts experienced by adolescents may be conceptualized on a severity continuum . Stakeholder consensus on perceptions of challenges and perceived harms formed the second theme, with impacts further analysed as relating to time displacement, peer judgement, sensory overload and context of the adolescent with functional (performance, task switching, use of multiple devices), cognitive (loss or deterioration of attentional focus, attention deficit), and emotional consequences (stress, anxiety, obsessive-compulsive/checking behaviours). A third theme formed was individual vulnerabilities predisposing poor mental health outcomes . The final theme related to impacts dependent on context and meaning attached . Findings suggest a consideration of a spectrum approach encompassing a broader range of potential psychological challenges and perceived harms beyond safety concerns and addiction in understanding problematic adolescent online experiences . Understanding perceived harms can aid the objective setting of interventions and consideration of mental health literacy in school curricula.