question: AIMS: To explore i) associations between vaping and self-reported diagnosed/suspected Covid-19; ii) changes in vaping since Covid-19 and factors associated with these changes; iii) whether Covid-19 motivated current or recent ex-vapers to quit. METHODS: Cross-sectional online survey of 2791 UK adults recruited 30/04/2020–14/06/2020. Participants self-reported data on sociodemographic characteristics, diagnosed/suspected Covid-19, vaping status, changes in vaping and motivation to quit vaping since Covid-19. RESULTS: There were no differences in diagnosed/suspected Covid-19 between never, current and ex-vapers. Bayes factors indicated there was sufficient evidence to rule out small negative (protective) associations between vaping status and diagnosed/suspected Covid-19. Among current vapers (n = 397), 9.7% (95% CI 6.8-12.6%) self-reported vaping less than usual since Covid-19, 42.0% (37.2-46.9%) self-reported vaping more, and 48.3% (43.4-53.2%) self-reported no change. In adjusted analyses, vaping less was associated with being female (aOR = 3.40, 95% CI 1.73-6.71), not living with children (aOR = 4.93, 1.15-21.08) and concurrent smoking (aOR = 8.77, 3.04-25.64), while vaping more was associated with being younger (aOR = 5.26, 1.37-20.0), living alone (aOR = 2.08, 1.14-3.85), and diagnosed/suspected Covid-19 (aOR = 4.72, 2.60-8.62). Of current vapers, 32.2% (95% CI 27.5-36.8%) were motivated to quit vaping since Covid-19, partly motivated by Covid-19, and 21.0%, (10.5-31.4%) of recent ex-vapers quit vaping due to Covid-19. CONCLUSIONS: Among UK adults, self-reported diagnosed/suspected Covid-19 was not associated with vaping status. Half of current vapers changed their vaping consumption since Covid-19, with the majority reporting an increase, and a minority was motivated to quit due to Covid-19. REGISTRATION: The analysis plan was pre-registered, and it is available at https://osf.io/6j8z3/