Conjunctival melanoma is a rare neoplasia, whose therapeutic management is generally of ophthalmological relevance, through radical surgical resection. The high incidence of local relapses after surgery, has made it necessary to combine various types of adjuvant treatments, which in some cases take on the role of radical treatments. Among these non-surgical treatments, those involving the application of ionizing radiation are becoming particularly important. In this review, we discuss the role of episcleral brachytherapy, external photon-beam radiotherapy, also made through stereotactic or radiosurgical modality, and of proton-beam radiotherapy. We try also to take stock of the benefits of the different irradiation modalities and the application difficulties of each.