Background and objectives: It is unknown whether bullying and gender diversity are associated with increased headache frequency in adolescents. Our study aimed to assess the association between peer victimization, gender diversity, and frequent recurrent headaches in adolescents, while controlling for age, sex, socioeconomic status, and potential confounders (mood and anxiety disorders, suicidality). Methods: This was a cross-sectional observational study of adolescents aged 12-17 using data from a Canadian population-based health survey. Headache frequency was dichotomized into ‘≤once/week’ or ‘>once/week’ (i.e. frequent recurrent headaches). Logistic regression was used to quantify the association between frequent peer victimization (overt or relational), gender diversity (female sex at birth+male gender, male sex at birth+female gender, or gender diverse), mood/anxiety disorder, suicidality, and the odds of frequent recurrent headaches. The fully adjusted multivariable logistic regr