ABSTRACT: BACKGROUND:Many adolescents with obesity do not meet recommendations for nutrition, physical and sedentary activities, and sleep habits, all of which can influence weight management. OBJECTIVE:To explore barriers and enablers that influenced the adoption of lifestyle behavior changes among adolescents receiving multidisciplinary clinical care for pediatric weight management. METHODS:In this multi-centre, qualitative description study, we used purposeful sampling to recruit 13-17 year olds (body mass index ?85th percentile) enrolled in one of two pediatric weight management clinics in Edmonton and Ottawa, Canada. Adolescents participated in one-on-one, in-person, semi-structured interviews in English or French. Interviews lasted 30-60 minutes, were audio-recorded, transcribed verbatim, and managed using NVivo 11. Data were triangulated using transcripts, field notes, and memos and analyzed by two independent researchers using inductive, semantic thematic analysis. RESULTS:In total, 19 adolescents (12 Anglophone and 7 Francophone; 15.1±1.7 years old; 3.5±0.6 BMI z-score; n = 11 female; n = 13 Caucasian) participated. Adolescents reported diverse barriers to and enablers of healthy nutrition, physical and sedentary activities, and sleep habits, which we organized into the following themes: physiological mechanisms and physical health status, self-regulation for behavior change, controllability and competence beliefs, social relationships and interactions, and accessibility to and availability of opportunities for lifestyle enhancement. Across these themes and lifestyle areas, we identified three shared barriers and/or enablers, including the degree of controllability, the impact of mental health, and social pressures related to weight management. CONCLUSIONS:This research provides evidence that can be used to tailor interventions and health services delivery, including a focus on psychosocial well-being, to support adolescents with obesity in making and maintaining healthy lifestyle behavior changes.