Aim: Dental healthcare professionals are at a considerable risk of infectious diseases such as hepatitis B (HB). The study aims to present the details on the current knowledge, attitude, and practice of dental students towards HB in the Kingdom of Saudi Arabia. Materials and methods: A cross-sectional study was designed targeting fifth academic year and 6th academic year dental students as well as dental interns. Knowledge, attitude, and practice of HB were checked using a self-reported questionnaire. Wherein, 11 questions were about knowledge, 6 about attitude, and the final 6 were on practice. Chi-square analysis was followed by Spearman's correlation to report on the relation between knowledge, attitude, and practice. SPSS version 24 was used for analyzing the data. Results: The response rate was 87% of which, 41% were females, and 59% were males. It was seen that 61.3% of the respondents had good knowledge, 55% indicated a positive attitude, and 77% of them demonstrated safe practices. We also observed that the students or interns with good grade point average (GPA) had the strongest correlation (r = 0.70; p < 0.001) with their knowledge on HB. Knowledge was also significantly correlated with the attitude (r = 0.373, p < 0.001 and safe practices (r = 0.11, p = 0.004) of HB among the students and the interns. Conclusion: Findings from the current research conclude that having good knowledge on HB accounts for a positive attitude and safe practices among undergraduate dental students. Clinical significance: Potential oral health practitioners at dental schools should have a thorough knowledge of infectious diseases such as HB so that they implement safe practices from an early stage. The medical and dental curriculum should be reformed to include specific learning outcomes in every clinical course on stringent and effective ways to implement infection control practices.