Background: Attention deficit hyperactivity disorder (ADHD) is consistently associated with poor school-level outcomes. Although school engagement is recognized as a protective factor associated with increased academic achievement, school retention/completion, and student well-being in the general population, little research has focused on school engagement in children with ADHD. Aims: To explore a model of the relationships between ADHD symptoms at age 7, student-teacher closeness and conflict at age 10, and emotional engagement with school at age 10 and 12. Sample: Participants were 498 grade one children (mean age = 7.3), recruited from 43 socio-economically diverse government primary schools in Melbourne. Follow-up occurred at 36 months (mean age = 10.5) and 54 months (mean age = 12.0). Methods: Data were drawn from a controlled community-based longitudinal study examining the long-term effects of ADHD on children's behaviour, learning, and day-to-day living. Data were collected via direct assessment and child, parent, and teacher surveys. Results: Path analysis revealed a significant, negative relationship between ADHD symptoms and emotional engagement with school, which was partially mediated by student-teacher conflict. This remained significant after controlling for differences in ADHD status (ADHD, high-risk, or control group), ADHD medication use, and socio-economic status. Conclusions: These findings highlight the negative impact of ADHD symptoms on children's emotional engagement with school. Given the role of student-teacher conflict in mediating this relationship, interventions aiming to reduce conflict in the student-teacher relationship may promote school engagement for students with ADHD, with potential to improve longer-term outcomes.