RecruitingBehavioural interventionComparing Two School-Based Sleep Health Interventions To Promote Sleep Quality in YouthThe goal of this clinical trial is to conduct a comparative effectiveness trial that will evaluate two school-based interventions to improve adolescent sleep health: the standard Sleep Health Education (SHE) and a stepped care version of the Transdiagnostic Sleep and Circadian intervention (TS-C-STEP). The main questions it aims to answer \[is/are\]: * TS-C-STEP will yield superior outcomes relative to SHE at post-treatment and up to 12 months following treatment. * In this large and diverse sample, vulnerable subgroups (e.g. socioeconomically disadvantaged, racial, ethnic, rural, and youth with comorbid learning and/or mental health conditions) will experience greater benefits from TS-C-STEP compared to SHE on primary and secondary outcomes. Researchers will compare sleep quality to determine which intervention is most effective.