Introduction: The Diabetes Control and Complications Trial (DCCT) clearly documented long-term beneficial effects on both micro- and macrovascular complications associated with type 1 diabetes (T1D) by using intensive insulin therapy (IIT) via multiple daily injections or insulin pumps more than 30 years ago. IIT, both during the DCCT and with translation into clinical practice, has been demonstrated to increase the risk of severe hypoglycemia and weight gain. Automated insulin delivery (AID) systems have become the standard of care in T1D management in the developed countries. Materials and Methods: We reviewed the registration and real-life studies for different AID systems reported to date. Many of the registration studies were sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases. A systematic literature search was conducted using the MEDLINE (PubMed) database. Studies with the longest duration and/or with the largest number of participants were included. Results: In the last decade, the introduction of many AID systems for patients with T1D has shown improvements in glycemic metrics as documented by hemoglobin A1c values, time in range, time below range, and quality of life. Most of the registration and real-life studies have shown safe and effective use of AID systems for all age groups living with T1D. Conclusions: In this review, we summarize the registration and real-life studies of U.S. Food and Drug Administration-approved AID systems. Real-life studies confirmed the glycemic outcomes of AID systems reported from registration studies.