Oral cancer represents a major public health challenge worldwide and disproportionately affects older adults due to cumulative exposure to carcinogens combined with age-related biological changes, including genomic instability, chronic inflammation, impaired immune surveillance, and epigenetic dysregulation, all of which increase susceptibility to oral carcinogenesis. The burden of disease is further amplified by comorbidities and age-associated functional decline, which may complicate both prevention and treatment in geriatric populations. This review synthesizes current knowledge on molecular mechanisms linking aging biology with oral cancer development and discusses major etiological risk factors prevalent in geriatric populations, including tobacco use, alcohol consumption, dietary deficiencies, oral microbiome dysbiosis, obesity-associated inflammation, and human papillomavirus infection. The review also outlines evidence-based strategies for prevention and early detection, emphasizing lifestyle modification, smoking cessation, improved oral hygiene, and emerging chemopreventive approaches. Finally, we highlight current challenges in oral cancer screening and early diagnosis and discuss the diagnostic relevance of novel molecular biomarkers, which may support earlier detection and more accurate risk stratification.