High human papillomavirus (HPV) prevalence and low HPV vaccine uptake are significant public health concerns. Disparities in HPV-associated cancers and HPV vaccine uptake rates suggest the need for additional research examining factors associated with vaccine acceptance. This study assessed HPV awareness and knowledge and identified sociodemographic characteristics associated with HPV knowledge at the population level. Data from adult men (n = 1,197) and women (n = 1,906) who participated in the National Cancer Institute’s 2014 Health Information National Trends Survey were analyzed. Multivariable regression was used to identify predictors of four HPV knowledge categories: (1) general knowledge, (2) cervical cancer knowledge, (3) “other” cancer knowledge (i.e., anal, oral, penile), and (4) vaccine knowledge. Significant gender differences in awareness and knowledge of HPV and the HPV vaccine were revealed. Most participants (>70%) knew that HPV could cause cervical cancer, but fewer (14.9% to 31.5%) knew of the association between HPV and “other” cancers. Women were more likely to report that a health care provider recommended vaccination. Significant predictors of general HPV and HPV vaccine knowledge included gender, education, income, race, and other sociodemographic characteristics. Age and income predicted cervical cancer knowledge. Knowledge of “other” HPV-associated cancers was predicted by having a child under 18 years in the household and relationship status. HPV knowledge appears to be socially patterned. Low HPV knowledge among men and some racial minorities suggests a need for further intervention. Health education should emphasize risks of noncervical HPV-associated cancers. Patient–provider communication that includes education, counseling, and clear recommendations favoring vaccination may improve uptake.