Giant cell tumor (GCT) is a common benign aggressive tumor that mostly occurs in the proximal tibia, distal radius, and distal femur but is rarely seen in the distal region of the humerus. It originally presents between the ages of 30 and 50 with suddenly occurring pain. Treatment is generally curettage adjuvant treatment if necessary and reconstruction if required. In our case report, we present the clinical and radiological findings, diagnosis, and management of a 33-year-old female patient with a giant cell tumor (GCT) accompanied by a secondary aneurysmal bone cyst (ABC) in the left distal humerus, where the patient experienced pain for many years without significant history of trauma. Upon clinical examination, the patient displayed tenderness over the medial side of the elbow but no noted swelling, redness, or hotness. She had a painless full range of motion, with an intact distal neurovascular examination. Imaging concluded GCT with secondary ABC. A biopsy confirmed the diagnosis, ruling out metastatic lesions. The patient underwent surgical intervention, with plate fixation, which yielded excellent outcomes.