Background: Periodontal health is a critical component of overall well-being, yet its importance often remains underexplored among future healthcare providers. This study aimed to assess the knowledge, awareness, and practices regarding periodontal health among undergraduate medical students in Puducherry. Methods: A descriptive, cross-sectional online survey was conducted among 660 undergraduate medical students (aged 18–25) at Sri Venkateshwara Medical College Hospital and Research Centre. Data were collected using a validated 25-item close-ended questionnaire covering knowledge, attitudes, and oral hygiene practices. Statistical analysis was performed using SPSS version 27. Results: While 94.7% of participants recognized that oral hygiene is mandatory for overall health, significant gaps in practice and specific knowledge were identified. Although 53.94% of respondents reported brushing twice daily, 49.09% utilized the less effective horizontal brushing technique. Usage of interdental cleaning aids was low, with only 8.64% reporting the use of dental floss. Furthermore, 58.94% of students had never visited a dentist in the past 12 months. Regarding disease progression, 36.36% were unaware that untreated periodontal disease could lead to tooth loss. Awareness of the link between oral health and systemic conditions, such as PCOS (61.21%) and medication-induced gingival enlargement (70.15%), showed room for improvement. Conclusion: Despite a general awareness of the importance of oral health, medical students exhibit significant gaps in evidence-based periodontal practices and preventive care. Integrating structured oral health education into the medical curriculum is essential to prepare future clinicians for holistic patient care.