Refractory recurrent aphthous stomatitis (RRAS) manifests as severe ulcerative lesions of the oral mucosa with poor healing and a poor response to conventional therapy, with or without systemic diseases. Its treatment remains a clinical challenge owing to the lack of effective therapies. Recently, biologics have emerged as promising targeted therapies for RRAS. The biologics targeting specific inflammatory pathways involved in the pathogenesis of RRAS, including tumor necrosis factor-alpha inhibitors and interleukin inhibitors, offer a more precise and promising therapeutic approach for RRAS. These targeted therapies have been shown to promote healing and decrease recurrence frequency in, and improve the quality of life of patients with RRAS. Herein, the types and mechanisms of biologics currently used to treat RRAS have been reviewed; furthermore, the dose, duration, therapeutic efficacy, and adverse effects of RRAS with or without certain associated systemic diseases, and the current problems and future directions have been discussed.