Obstructive sleep apnea (OSA) is the most common globally prevalent sleep disordered breathing. It is associated with various orofacial malformations and systemic morbidities. The limited level of awareness has left most cases undiagnosed. This study assessed the level of awareness of OSA and its orofacial and systemic complications among dental patients at the Lagos State University teaching hospital (LASUTH), Lagos, Nigeria. It was cross-sectional, involving 120 consenting subjects. Sample selection was by convenient sampling. Data collection was conducted using a self-administered questionnaire to obtain the biodata and the participants' awareness of OSA using the Likert scale. Data analysis was carried out using SPSS version 24 to assess the descriptive variables and OSA awareness of the subjects. Ordinal logistic regression was used to determine the relationship between the covariates and the participants' awareness of OSA. Statistical significance was determined at p≤ 0.05. The mean age of the participants was 45.7±16.2 years. A few, 23(19.2%), were fully aware of what OSA is. Twenty-six (21.7%) were fully aware that OSA can predispose to dental problems. Seventy-one (59.2%) were aware to a limited extent that some orofacial symptoms could identify people with OSA. Only 27(22.5%), 24 (20%), and 23 (19.2%) were fully aware that OSA is related to high blood pressure, obesity, and sudden death, respectively. In an ordinal regression, the age groups and occupational groups were the determinants of the participants' awareness about OSA (p≤0.05). Intensive education of the population is needed through several forums to increase their awareness of OSA and its complications.