Idiopathic sudden sensorineural hearing loss is an unexplained sudden loss of sensorineural hearing, with no specific pathogenesis, and is difficult to treat. The most common therapeutic strategy for idiopathic sudden sensorineural hearing loss is the use of steroids combined with neurotrophic drugs, as other treatments have shown limited efficacy. However, in recent years, hyperbaric oxygen therapy has emerged as a promising treatment option. Studies have shown that hyperbaric oxygen therapy, in combination with conventional treatments, can effectively alleviate inner ear edema, improve blood circulation, and suppress inflammation. Therefore, hyperbaric oxygen therapy plays an important role in the treatment of idiopathic sudden sensorineural hearing loss. In this review, we aim to assess existing studies and summarize the clinical effects and mechanisms of hyperbaric oxygen therapy in idiopathic sudden sensorineural hearing loss, providing a basis for further research on the clinical treatment of this disorder.