We present two cases of head and neck squamous cell carcinoma (SCC) metastasizing to the thyroid gland. This is the first report that shows (18) F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) images of tonsillar and supraglottic SCCs invading the thyroid gland. Alcohol and tobacco use are the two most important risk factors for head and neck cancers, but recently human papilloma virus (HPV) infection has become a significant risk factor in the United States. FDG-PET/CT is very useful for SCC staging/restaging and follow-up.