Fibrous histiocytoma (FH) within the finger, particularly involving the flexor tendon sheath, is a rare entity. While cutaneous fibrous histiocytomas have been documented in the fingers, their occurrence around the flexor sheath presents a unique diagnostic challenge, often resembling giant cell tumor of the tendon sheath (GCTTS). We report a case of benign fibrous histiocytoma involving the tendon sheath in the index finger of a 70-year-old patient and discuss its clinical presentation, differential diagnoses, histopathological features, and management.