Dimensions of family-school partnerships, including parent-teacher relationship quality and family educational involvement, are associated with positive outcomes for youth. Family-school partnerships are important for autistic youth, who may particularly benefit from cross-setting supports. Coordinated family-school partnerships may help maximize child outcomes. This study investigated the extent to which child behavioral and physical health (emotional, behavioral, and medical problems) and parent mental health (parenting stress, parent mental health history, and parent depressive symptoms) were associated with parent-teacher relationship quality and family involvement in a sample of 68 families of school-aged autistic children. Families were recruited through invitation letters disseminated at local early intervention and early childhood programs. Children in the sample were primarily boys, primarily White, and approximately 8 years old. Results suggest that (a) child emotional problems and parenting stress were negatively associated with parent-teacher relationship quality (large effects) and (b) parent history of mental health problems was negatively associated with family involvement (large effect). Intervention recommendations and future research directions are discussed. For example, it would be helpful for future research to include the perspectives of ethnically diverse samples when examining family-school partnerships among families with autistic children.