Calcaneum tuberculosis (TB) is a rare entity, though it is the commonly involved tarsal bone. It does not present with the typical features of TB and can be confused with other pathologies affecting the heel. Very few case reports and case series studies are present to date for describing this rare entity. We report a 23-year-old female who presented to the orthopedic outpatient clinic with pain and swelling around the left heel and posterior aspect of the ankle for 3 months. Her radiograph showed a lytic lesion in the posterosuperior aspect of the calcaneum. Therefore, magnetic resonance imaging was done, which showed a lesion around the posterior-superior aspect of the calcaneum with the involvement of retrocalcaneal bursa. An incisional biopsy was performed, followed by en bloc excision of the lesion. The histopathological examination report suggested granuloma formation with caseous necrosis and the cartridge-based nucleic acid amplification test was also positive for mycobacterial TB infection. Proper clinical history, radiological examination, and biopsy are of utmost importance in these rare entities as they help in making the definitive diagnosis. Anti-Koch treatment is an effective treatment for TB, and the patient improved within 2 months of treatment both clinically (pain, swelling, and activity of daily routine) and radiologically (for bone formation and no recurrence). This report aimed to present a lytic lesion of the calcaneum that turned out to be TB and its management. The follow-up was 18 months post-surgery and showed no signs and symptoms of recurrence.