A solitary fibrous tumor is a relatively uncommon neoplasm that usually occurs in the pleura but occurs extremely rarely in the oral cavity. Reported herein is a rare case of a solitary fibrous tumor in the buccal cheek mucosa. A 50-year-old man visited the authors' hospital due to a buccal cheek mass whose size had increased. Excisional biopsy was done under local anesthesia. After the excisional biopsy, the patient was diagnosed to have a solitary fibrous tumor. In immunohistochemistry, the patient's solitary fibrous tumor was characterized by the expression of CD34 and CD99 on the neoplastic cells, and negativity for Bcl-2 and S-100. No recurrence or complication occurred for a period of 5 years. The growth of a primary solitary fibrous tumor in the buccal cheek mucosa is extremely rare and has been rarely reported in the South Korean medical literature. A solitary fibrous tumor must be distinguished from other spindle cell tumors. Presented herein is a case of primary solitary fibrous tumor in the buccal cheek mucosa. The relevant literature is briefly reviewed.