Objectives To explore how the use of, and trust in, different sources of advice and information on COVID-19 differed across the four UK nations and between different sociodemographic groups and their associations with COVID-19 vaccination status. Methods We used a UK-wide representative survey conducted in July 2021, which included data on uptake of COVID-19 vaccination, trust in information sources, use of sources and geographical and sociodemographic variables. We used multivariate logistic regression to identify factors associated with completed or planned COVID-19 vaccination. Results Trust in the NHS, followed by trust in scientists, were the strongest predictors of vaccination intention. NHS websites were the most used (56% across the UK); only the Scottish government website had a higher level of reported use (58%). Using either source was associated with a positive vaccination status as were use of the GP and television as sources of advice. Use of social media, family and friends, and ‘none’ of the sources enquired about, were all linked to a lower likelihood of being or intending to get vaccinated. Compared to those in England, respondents in other UK nations were less likely to trust the central UK government for advice on COVID-19. There was considerable variation by age in trust and use of some, but not all, sources of advice, with predicted probabilities ranging from 35% among the youngest age group to 62% among those aged 65 years or older. There were also significant differences by annual household income and by occupational class for trust in government, with higher incomes correlating with greater likelihood of trust. Conclusions This study demonstrates high levels of trust in the key sources of public health advice and there was a positive association between using official sources of advice and vaccination intentions, even in the context of overall high vaccination rates. Our findings highlight the need for the UK and devolved governments to value the importance of public trust in the health system and take appropriate measures to avoid undermining such trust.