Head and neck cancer is a group of cancers that are linked by a shared anatomical space. The anatomical space includes structures that are critical for speech, swallowing, breathing, vision, and hearing. It has long been recognized that head and neck cancer and its therapy adversely impact function. Rehabilitation in the head and neck cancer population is often challenging: it requires the coordinated care of experienced clinicians spanning a wide array of specialties. This chapter begins with a discussion of the socioeconomic considerations that are paramount in treating head and neck cancer patients. This is followed by a broad overview of the epidemiology, etiology, pathology, and staging of head and neck cancers. The chapter then discusses the specific modalities of therapy used in the treatment of head and neck cancer with an emphasis on the associated toxicities. Finally, it discusses site-specific considerations that impact functional outcomes.