Radiation therapy (RT) is indicated either in the definitive management of head and neck cancer (with concurrent chemotherapy for locally advanced disease) or in the postoperative setting (±concurrent chemotherapy) if there are high-risk features. This chapter discusses head and neck radiotherapy. It presents the site-specific indications, target volumes and special considerations for different types of head and neck cancers: oropharynx cancer; larynx cancer; hypopharynx cancer; nasopharynx cancer; major salivary gland cancer; oral cavity cancer; cancer of unknown primary; maxillary sinus cancer; nasal cavity/vestibule cancer; thyroid cancer; nonmelanomatous head and neck skin cancer; and head and neck melanoma.