Tuberculous osteomyelitis of the mandible is an extremely rare form of extrapulmonary tuberculosis that often mimics odontogenic infections, leading to diagnostic delays. A 16-year-old female presented with a painless, progressively enlarging swelling in the left mandible with intraoral pus discharge. Radiographic evaluation revealed an ill-defined radiolucent lesion with cortical loss, resembling odontogenic pathologies. Surgical drainage, sequestrectomy, and histopathological examination demonstrated granulomatous inflammation with Langhans-type giant cells and caseous necrosis. CBNAAT confirmed Mycobacterium tuberculosis, prompting the initiation of anti-tubercular therapy (ATT). The patient showed complete resolution at a 3-month follow-up. Mandibular TB is a rare entity requiring a high index of suspicion. CBNAAT serves as a rapid and reliable diagnostic tool, aiding early intervention. Timely ATT combined with surgical debridement ensures optimal outcomes.