Background: Obesity is one of the most neglected public health problems affecting both developed and developing countries. The most clinically severe obesity (Class 3 obesity) has both clinical and service delivery implications on dental services. However, associations between Class 3 obesity and oral health are minimally explored in the literature and thus poorly understood. Aims: This scoping review aimed to explore the existing evidence on Class 3 obesity and oral health. Methods: A literature search was performed via Medline, Scopus, Google scholar and Embase research databases. Results: A total of 375 papers were sourced from the database search. Twenty seven full-text papers were included in the final literature review. Results revealed findings from both quantitative and qualitative studies. Papers included results pertaining to associations with dental disease, oral health and associated behaviours, oral health-related quality of life and the barriers experienced by adults with Class 3 obesity in accessing dental services. Conclusions: While mixed findings were identified, this scoping review reports associations between Class 3 obesity and poor oral health across various domains including clinical parameters and oral health related quality of life. The literature has also highlighted important barriers to dental care in those with the most severe Class 3 obesity. Based upon our findings, we have summarised current oral health management implications and directions for future research.