Aims To describe a rare case of Glycogenic Acanthosis (GA) on the tongue of an older patient, emphasizing its clinical presentation, diagnostic challenges, and management approach while adding to the limited literature on this condition. Methodology: An 89-year-old Tongan male presented with a six-month history of atraumatic, non-tender, enlarging area of leukoplakia on the tongue. Medical history included chronic obstructive pulmonary disease (COPD), a 50 pack-year smoking history, and hypertension. Clinical examination revealed a 7 x 8 mm raised, well-circumscribed white lesion on the right lateral tongue, and an otherwise unremarkable head and neck examination and flexible nasoendoscopy. Two punch biopsies were performed under local anaesthesia, removing the lesion in its entirety. Results: Histopathology revealed exophytic, acanthotic surface squamous epithelium without papillomatosis, keratosis, or ulceration. Clear cytoplasm within epithelial cells stained positively for period acid-Schiff (PAS) and diastase confirming intracytoplasmic glycogen deposits consistent with GA. No dysplasia or malignancy was identified. The lesion resolved completely post-biopsy. The patient was reassured, no further interventions were required, and he was scheduled for annual monitoring to ensure stability. Conclusion: Glycogenic Acanthosis is a benign lesion most commonly found in the oesophagus, with tongue involvement being exceptionally rare. Only three cases of GA on the tongue have been reported in the literature. By expanding the differential diagnosis for white tongue lesions, this case highlights the importance of early recognition to avoid overtreatment, enhance patient outcomes, and contribute to the limited knowledge of GA in the oral cavity.