This study examined relationships between adverse childhood experiences (ACEs), school experiences and adult health outcomes in a sample of the Welsh adult general population. It found ACEs and negative school experiences (having been bullied and lower sense of school belonging) were independently associated with poorer adult mental health. Experiencing both ACEs and negative school experiences exacerbated risks of poorer mental health. The study indicates the protective role that schools may play in fostering resilience among children who experience adversity in home settings.