The aim of the study was twofold: (1) to examine how psychosocial support provided by teachers and classmates related to students' self-regulated learning as expressed through self-reported academic initiative, and (2) whether academic competence and school satisfaction mediated these relationships. The data were from a nationally representative sample of 13- and 15-year-old students (n = 3,125) from the Norwegian part of the World Health Organization's survey of Health Behaviour in School-aged Children. Multiple-group structural equation modeling analysis indicated that teacher support and classmate support related to academic initiative. A multi-mediating path approach revealed that school satisfaction partly mediated both these relationships. Perceived academic competence partly mediated the relationships between teacher support and academic initiative, and between school satisfaction and academic initiative. (Contains 2 figures and 4 tables.)