Oral focal mucinosis (OFM) is an extremely rare benign lesion of the oral cavity with unknown etiology, considered the oral counterpart of cutaneous focal mucinosis. It occurs mainly in women in the fourth and fifth decades of life. It has no characteristic features, and diagnosis depends on histological evaluation. Its pathogenesis is related to the excessive production of hyaluronic acid by fibroblasts during collagen production, which leads to focal myxoid degeneration. To date, ten documented cases have been reported in the literature in adolescents. This paper reports a rare case of OFM with a narrative review of the available literature.