Mental health conditions are a common comorbidity among children living with heart disease. Children with congenital heart disease are more likely to have a mental health condition than their unaffected peers or peers with other chronic illnesses, and mental health risk persists across their lifetime. While poorer mental health in adults with congenital heart disease is associated with worse overall health outcomes, the association between mental health and cardiac outcomes for children with heart disease remains unknown. Despite this, it is suspected that mental health conditions go undiagnosed in children with heart disease and that many affected children and adolescents do not receive optimal mental health care. In this article, we review mental health in congenital heart disease across the lifespan, across domains of care, and across diagnoses. Further directions to support mental health care for children and adolescents with heart disease include practical screening and access to timely referral and mental health resources.