A 15 year-old spayed female domestic cat presented with a subcutaneous mass on the ventral side of the external ear canal. A salivary gland tumor was suspected, and its size continued to increase. On day 49, a mass protruding from the ventral edge of the parotid gland was surgically excised. The mass was diagnosed as an oncocytoma by histopathological examination, histochemical staining, and immunostaining for cytochrome C. No recurrence or metastasis has been observed for 17 months after the operation. This is the first report of parotid gland oncocytoma in a cat with long-term postoperative survival.