Dentists are uniquely positioned to identify patients at risk of obstructive sleep apnea (OSA) and its complications. However, previous reports have shown that the average general dentist possesses insufficient knowledge about the clinical manifestations and complications of OSA. Aim: The purpose of this study was to examine Saudi dental interns’ knowledge related to the clinical manifestations and impact of OSA. Materials and methods: This was a cross-sectional study using a self-administered questionnaire to assess the interns’ knowledge related to the symptoms, signs, diagnosis, risk factors, and complications of OSA in adults and children. Results: The average of the proportions of factually correct participant responses of the questionnaire categories was 47%. Participants did best in the category of questions related to predisposing factors (50% of questions were answered correctly), but less than 50% of questions were answered correctly in other OSA-related areas. Most participants scored 49% or lower in this questionnaire. Conclusion: Saudi dental interns had poor knowledge related to OSA. This may relate to the insufficiency of teaching sleep-related topics in dental curricula, among other reasons. Clinical significance: Given the potential impact of OSA on cardiovascular health, metabolic syndrome, and other public health problems, it is important to remedy this knowledge gap and empower future physicians with the knowledge required to participate in detecting OSA patients and referring them for evaluation.