Comprehension of the factors which promote young people’s well-being is important, particularly during adolescence. This article investigates how family and school factors affect life satisfaction as an indicator of well-being. It examines a representative sample of 5440 Australian students in Years 4, 6, and 8, who completed a child-centred survey as part of the Australian Child Wellbeing Project. Classification tree analyses are used to show that high life satisfaction is associated with family cohesion (families have fun together), and with schools, if they are places that are free from bullying, where students like to go, and where teachers believe in their success. These findings will interest policy makers and practitioners aimed at improving the well-being of adolescents by promoting the importance of family cohesion, and by supporting schools to implement anti-bullying policies which use a variety of instructional methods based on high expectations.