Background: Approximately 90% of patients express concerns with sleep shortly after developing shoulder-related symptoms. Previous small cohort studies have demonstrated the impact of rotator cuff repair (RCR) on sleep, but none have characterized the observed benefits. The purpose of this study is to evaluate sleep improvement after rotator cuff repair including the speed of sleep recovery, the time at which improvement plateaus, and the longer-term maintenance of improved sleep. Methods: A retrospective review of our institution's shoulder and elbow repository identified patients who underwent primary arthroscopic rotator cuff repair from 2012 to 2021 and reported sleep disturbance preoperatively. Patients were evaluated using sleep-related questions from the Simple Shoulder Test and American Shoulder and Elbow Surgeons score. Sleep outcomes were compared from a preoperative visit to 3month, 6-month, 12-month, and most recent follow-ups to evaluate efficacy of treatment, speed of recovery, and improvement plateaus. Results: Among 677 RCR patients, 95.7% (648/677) reported sleep disturbance preoperatively. A total of 474 met inclusion criteria with median follow-up of 4.1 years (IQR, 2.1-6.1). At most recent follow-up, 81.8% were able to sleep comfortably and 65.7% were able to sleep on the affected side. A plateau in the ability to sleep comfortably was seen at 6 months while no plateau was observed in the ability to sleep on the affected side. More rapid improvement in the ability to sleep comfortably occurred during the first 3 months and from 36 months for the ability to sleep on the affected side. Conclusion: The majority of patients with sleep disturbance who undergo RCR, report significant, rapid, and lasting improvement in the ability to sleep comfortably and the ability to sleep on the affected side. Level of evidence: Level IV; Case Series; Treatment Study (c) 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights are reserved, including those for text and data mining, AI training, and similar technologies.