Background: Experiencing multiple adverse childhood experiences (ACE) is a risk factor for many adverse outcomes. However, the role of family and socioeconomic factors in these associations is often overlooked. Methods and findings: Using data from the Avon Longitudinal Study of Parents and Children, we assess associations of ACE between birth and 16 years (sexual, physical or emotional abuse, emotional neglect, parental substance abuse, parental mental illness or suicide attempt, violence between parents, parental separation, bullying, and parental criminal conviction) with educational attainment at 16 years (n=9,959) and health at age 17 years (depression, obesity, harmful alcohol use, smoking and illicit drug use, n=4,917). We explore the extent to which associations are robust to adjustment for family and socioeconomic factors, whether associations differ according to socioeconomic factors, and estimate the proportion of adverse educational and health outcomes attributable to ACE, family or socioeconomic measures. There were strong associations of ACE with lower educational attainment and higher risk of depression, drug use and smoking. Associations with educational attainment attenuated after adjustment but remained strong. Associations with depression, drug use and smoking were not altered by adjustment. Associations of ACE with harmful alcohol use and obesity were weak. We found no evidence that associations differed by socioeconomic factors. Between 5-15% of the cases of adverse educational and health outcomes occur amongst people experiencing 4+ ACE, and between 1-19% occur in people whose mothers have a low level of education. Conclusions: This study demonstrates strong associations between ACE and lower educational attainment and worse health that are independent of family and socioeconomic factors. Our findings imply that interventions that focus solely on ACE or solely on socioeconomic deprivation, whilst beneficial, would miss most cases of adverse educational and health outcomes. Intervention strategies should therefore target a wide range of relevant factors, including ACE, socioeconomic deprivation, parental substance use and mental health.