This study reviewed 31 articles on parental support and parent-school relationships of K-12 online students. Under the guidance of the Academic Communities of Engagement framework, this literature review explored existing studies on the interactions between online students' personal, course, and school community support. The challenges faced by parents and teachers are described in the discussion. By systematically analyzing the current research on recommended practices for online schools in supporting parents, the authors proposed five themes: (a) Strengthening school-parent communication by keeping parents updated on students' learning progress, (b) Collaborating with parents to help them become more knowledgeable about the content, technology, teaching, and parenting skills they need, (c) Increasing parental involvement in students' coursework and the school community, (d) Seeking for researcher-practitioner collaboration, and (e) Helping parents understand their new roles in supporting online students.