Radiation dermatitis (RD) is a prevalent adverse effect of radiotherapy, particularly in the treatment of head and neck cancer, affecting approximately 90–95% of patients. This condition commonly presents with symptoms such as erythema, hyperpigmentation, and dry or moist desquamation. To manage and mitigate these symptoms, clinicians employ a range of topical pharmacological treatments along with non-pharmacological strategies. Recent advancements in this field have highlighted the effectiveness of photobiomodulation therapy. Photobiomodulation appears not only to prevent and treat RD effectively but also to alleviate symptom severity and reduce the systemic impacts associated with prolonged pharmacotherapy.