Medical students are future healthcare leaders whose personal health behaviors influence their clinical advocacy. This study assessed oral hygiene knowledge, practices, and clinical status among medical students at the University of Dongola, Sudan, and explored barriers to maintaining optimal oral health. A cross-sectional survey was conducted between July and December 2024 among 208 students in Years 2 and 6, using a validated questionnaire and clinical examinations. Data included demographics, brushing habits, awareness of systemic links, and perceived barriers. Statistical analysis employed Pearson’s Chi-square test (P < 0.05). Most participants were female (66.0%) and aged 20–24 years. A significant knowledge–practice gap was observed: although 78.0% acknowledged oral health importance, only 41.0% brushed twice daily. Caries prevalence was 54.0%, and 67.3% were categorized as having poor oral hygiene. No significant associations were found between hygiene status and gender (P = 0.556) or academic level (P = 0.995). Academic workload was the most cited barrier (70.2%). Awareness of oral health links with diabetes (44.2%) and heart disease (30.8%) was limited. Findings reveal poor oral hygiene practices and high caries prevalence among medical students, highlighting the need for curriculum integration of oral health modules and preventive screening programs to foster healthier behaviors and effective health advocacy.