Research shows that school is one of the most important life domains shaping adolescents' life satisfaction (LS) and this influence varies across countries and different groups of students (e.g. by gender). However, there is a lack of cross-country comparative research studying the links between school and students' LS and how this differs across socioeconomic status (SES). This study explores this question using multilevel regression to analyse data from the 2015 Programme for International Students Assessment study on 15-year-old students in 33 countries. Two measures of SES were considered: material well-being and a composite SES measure. Results indicate that (1) in some countries, distinct school-related factors may shape students' LS differently for students of higher and lower SES, (2) although there are some general patterns across countries for some school factors (bullying, academic competence, and parents' support in relation to school are more strongly associated with LS among students of lower SES), for most school factors, the picture is mixed, and (3) in around half of the countries, schools seem to moderate the association between SES and students' LS. Research and policy implications are discussed.