PURPOSE Willingness of adults at high-risk of COVID-19 to receive a COVID-19 vaccine is unknown. There are key disparities in the risk and outcomes from COVID-19 by socio-demographic factors, including age, sex, level of deprivation, and ethnicity. A COVID-19 vaccination programme could inadvertently exacerbate these inequalities if it is not readily received by different population groups. In this UK-wide cross-sectional survey, we examined willingness to receive a COVID-19 vaccine in the general population and evaluated socio-demographic and clinical factors associated with willingness.METHODS Between April and June 2020, individuals in the general population were invited to complete an online survey; 2568 provided informed consent. Willingness to receive a COVID-19 vaccine was reported by 2152 (83.8%).RESULTS In total, 76.9% (1654/2152) reported being willing to receive a COVID-19 vaccine. One in five individuals at increased risk of COVID-19, as defined by UK government guidelines, were unwilling to receive a COVID-19 vaccine (119/589; 20.2%). Individuals from white ethnic group were more likely to be willing to receive a COVID-19 vaccine compared with those from BAME groups (79.9% vs. 55.9%, respectively), OR 2.84, 96% CI = 1.93 – 4.18, p ≤ 0.001. Willingness did not vary among adults at increased risk of COVID-19 compared with those not at increased risk.CONCLUSION A significant proportion of individuals in the general population are unwilling to receive a COVID-19 vaccine, including those at increased risk of COVID-19 morbidity and mortality. There are socio-demographic differences in willingness, especially by ethnic group. Success of a vaccination programme for COVID-19 depends not only on the efficacy of the vaccine but also on its uptake. Research is urgently needed to establish the most effective policy and communications to encourage maximal uptake of the vaccination.