Purpose <p>Sleep-related problems are common among Japanese university students. Students majoring in Sports and Health Sciences are generally more exposed to health-related education, yet those involved in extracurricular sports often maintain demanding routines that may constrain their sleep opportunity—potentially increasing their susceptibility to insufficient sleep. This study aimed to identify factors associated with sleep-related symptoms and excessive daytime sleepiness in Japanese undergraduate students majoring in Sports and Health Sciences.</p> Methods <p>A cross-sectional online survey was conducted from May to August 2024 among 3,284 students majoring in Sports and Health Sciences from four Japanese universities. Participants completed an anonymous questionnaire assessing sociodemographic characteristics, participation in extracurricular sports, lifestyle habits, psychological distress, exposure to health information, and sleep-related variables. Sleep-related symptoms and daytime sleepiness were assessed using validated scales. Multiple linear regression was used to examine associations between behavioral and psychological factors and sleep outcomes.</p> Results <p>A total of 841 students responded (25.6%), with 813 included in the analysis. Among them, 42.2% exceeded the cutoff for sleep-related symptoms and 35.2% for excessive daytime sleepiness. Later weekday bedtimes, earlier wake-up times, and psychological distress were associated with more sleep-related symptoms. Additionally, later bedtimes, gaming device use after lights-out, participation in extracurricular sports, and psychological distress were associated with greater daytime sleepiness.</p> Conclusions <p>These findings suggest that awareness not only of mental health and individual lifestyle behaviors but also of the scheduling constraints that limit sleep opportunity may be important for addressing sleep-related problems in this population.</p>