School belonging is an important avenue for exploration due to its associations with positive outcomes across behaviour, academic achievements and mental health. This study aimed to investigate differences between looked after and non-looked after young people, the associations between school belonging and related outcomes across groups, and factors that help young people feel they belong at school. Quantitative analysis of data from an anonymous online survey completed by looked after young people and matched participants revealed that school belonging was related to mental wellbeing outcomes for all participants. While school belonging and mental health scores did not differ between groups, looked after young people reported lower peer support. Based on within group correlations, three relationships were examined using moderation analysis which showed that the relationship between bullying and school belonging was moderated by care status. Based on qualitative data, young people across groups highlighted friends, teachers, school atmosphere and personal characteristics as important for their school belonging. The research was limited by sample size, but results suggest that a focus on mental wellbeing and school belonging remains important; this is discussed in relation to current educational practice and supporting school belonging within education settings.