Objective:This study aims to examine academic discourse on wearable devices for sleep, evaluating the domain's current landscape and identifying key research foci.Methods:The articles and reviews regarding wearable devices for sleep were culled from the Web of Science Core Collection, spanning the years 2004 to 2025. CiteSpace software was employed to visualize the knowledge map, including publication trends, country, author, journal, and keyword.Results:According to the search strategy, a total of 1572 published articles and reviews were retrieved. The number of publications and citations showed an increasing trend over the past 2 decades. Sensors was the most productive journal, while sleep was the most cited. The United States was the most productive country, followed by China and England. The University of California System was leading research hubs in this field. Hannah Scott published the most papers, and Massimiliano de Zambotti was the most frequently co-cited author. The review published by Massimiliano de Zambotti and Shahab Haghayegh in 2019 was the most influential publication. The most frequently occurring keywords in the field of wearable devices for sleep were "physical activity," "sleep," "wearable devices," "heart rate variability," "validation," "actigraphy," "machine learning," "health," "wearable device," "wearable sensors," "validity," and "polysomnography." The keyword "validity" had the highest burst rate, while "dynamics," "atrial fibrillation," "human activity recognition," "major depressive disorder," and "light" emerged as new research hotspots in recent years.Conclusions:This study provides a comprehensive overview of the current state of wearable device research in sleep science. By identifying key trends, influential researchers, and emerging research areas, this study offers valuable insights for future research and development in this field.