Lay Summary Patient portals provide patients access to health records, lab results, medication refills, educational materials, secure messaging, appointment scheduling, and telehealth visits, allowing patients to take a more active role in their health care decisions and management. This article systematically reviewed all literature regarding patient education through patient portals to determine its effectiveness in improving patient engagement and ability to manage their health conditions. The results found that efforts are being made to raise awareness of educational resources in patient portals, that patients are increasingly utilizing these resources, that patients are finding them useful, and that they are improving health outcomes. It seems that patient portals are becoming a powerful tool for patient engagement and show promise as a means of improving patients’ health. Continued efforts need to be made to raise awareness of patient educational resources in patient portals so that patients utilize these resources to increase their knowledge, skills, and confidence for managing their own health and health care.