The aim of the present study was to investigate variations between schools when it comes to gambling and risk gambling, and, in particular, to analyse the links between school collective efficacy and student gambling and risk gambling. The data consists of official register information on schools as well as survey data collected in 2016 among 1,061 teachers and 5,191 students in 46 Stockholm upper secondary schools. School collective efficacy was operationalized on the basis of teacher responses, which were aggregated to the school level. Gambling and risk gambling were based on students’ self-reports. Two-level binary logistic regression analyses were performed. The results show that there is between-school variation in gambling and in all the study’s indicators of risk gambling. Both gambling and risk gambling were more commonly reported by students attending schools with weak collective efficacy, even when adjusting for student- and school-level sociodemographic characteristics. The findings suggest that conditions at school may counteract students’ engagement in gambling and risk gambling.