Solitary fibrous tumor (SFT) is a rare spindle cell neoplasm that usually arises from the pleura. SFTs occurring within the head and neck region are uncommon. Recently, it has been described in various head and neck sites such as oral cavity, nasal cavity, paranasal sinuses, salivary glands, thyroid, buccal space, and larynx. Here, we report a case of SFT originating in the masseter muscle of a 27-year-old woman. To our knowledge, this is the first description of a SFT of the head and neck region, arising within the masseter muscle. We present the clinical history, radiologic and histopathologic findings as well as immunoreactivity of this tumor.