Head and neck cancers (HNC) are the seventh most common cancers worldwide. Early diagnosis of HNC is associated with better outcomes. This study aimed to assess public awareness of HNC among adults in Poland, with particular emphasis on awareness of HNC symptoms and risk factors for HNC. This cross-sectional study was carried out in November 2021 on a nationwide, representative sample of 1082 inhabitants of Poland aged 18 years and over. The computer-assisted web interview (CAWI) technique was used. Most of the respondents rated their knowledge of head and neck cancers as “a little” (40.8%) or “nothing at all” (30%). The most identified symptoms were a lump in the neck (57.9%) and swelling or a lump in the throat (51.8%). The most identified risk factor for HNC was smoking cigarettes/tobacco (63.1%). Excessive alcohol consumption and HPV infection were correctly identified as risk factors by about one-third of respondents. Public awareness of selected symptoms of HNC and risk factors for HNC differed by sociodemographic factors, of which the educational level was the most important factor associated with awareness of head and neck cancers (p < 0.05). This study demonstrated low public awareness of head and neck cancers among adults in Poland.