Given the results from early trials, COVID-19 vaccines will be available by 2021. However, little is known about what Americans think of getting immunized with a COVID-19 vaccine. Thus, the purpose of this study was to conduct a comprehensive and systematic national assessment of COVID-19 vaccine hesitancy in a community-based sample of the American adult population. A multi‐item valid and reliable questionnaire was deployed online via mTurk and social media sites to recruit U.S. adults from the general population. A total of 1878 individuals participated in the study where the majority were: females (52%), Whites (74%), non-Hispanic (81%), married (56%), employed full time (68%), and with a bachelor’s degree or higher (77%). The likelihood of getting a COVID-19 immunization in the study population was: very likely (52%), somewhat likely (27%), not likely (15%), definitely not (7%), with individuals who had lower education, income, or perceived threat of getting infected being more likely to report that they were not likely/definitely not going to get COVID-19 vaccine (i.e., vaccine hesitancy). In unadjusted group comparisons, compared to their counterparts, vaccine hesitancy was higher among African-Americans (34%), Hispanics (29%), those who had children at home (25%), rural dwellers (29%), people in the northeastern U.S. (25%), and those who identified as Republicans (29%). In multiple regression analyses, vaccine hesitancy was predicted significantly by sex, education, employment, income, having children at home, political affiliation, and the perceived threat of getting infected with COVID-19 in the next 1 year. Given the high prevalence of COVID-19 vaccine hesitancy, evidence-based communication, mass media strategies, and policy measures will have to be implemented across the U.S. to convert vaccines into vaccinations and mass immunization with special attention to the groups identified in this study.