Over the past fifty years, the topic of children's well-being has garnered attention in political and academic debates. In recent decades, the extensive literature on the topic has documented the numerous determinants of children's life satisfaction, as well as their relative importance according to cultural contexts. This increasing attention paid to children's subjective well-being includes consideration of school environments (see for example the ISCWeB study, HBSC study, the advancements of Positive Education, World Happiness Report 2015, etc). Until recently, the Program for International Student Assessment (PISA) surveys were mainly focused on well-being as linked with academic and professional achievement. Since 2015, PISA has documented ongoing levels of children's well-being, and how well-being is influenced by school environments, the quality of children's relationships with their peers and teachers at school, as well as parental involvement in the lives of their children. This article aims to highlight the impact of school-related determinants on children's life satisfaction and its variations across social classes. Based on the French part of the PISA 2015 Survey (n=4804), we have identified a two steps expression of inequalities. We begin by showing that class differences influence children's probability of having both a school environment and peer and parental relationships that enhance their level of life satisfaction. We go on to point out that social inequalities also appear when examining the impact of school-related factors on children's overall life satisfaction. It seems that school bullying, anxiety and parental involvement in school impact children differently depending on their social background.