The aim of this study was to examine how perceived support provided by teachers and classmates in the school class environment related to students' academic initiative. Data were from a stratified sample of 13-year-old students (n = 1591) from the Norwegian part of the World Health Organization's survey of Health Behaviour in School-aged Children (HBSC). Self-reported academic initiative varied across school classes with a difference (unexplained school class-level variance) of 12%. Perceived teacher support, defined as the provision of fairness and friendliness, varied substantially between classes. In two-level SEM analysis, a latent factor comprising pedagogical caring and autonomy support was substantially related to students' academic initiative at the class level. Perceived classmate support was significantly but moderately associated with academic initiative at the individual level. (Contains 4 tables and 1 figure.)