There is a long-standing debate in academic and policymaking circles about the normative merits and economic effects of a universal basic income (UBI). However, existing literature does not sufficiently address the question of which factors are associated with individual support for a UBI. While a large literature in political economy has focused on individual preferences for existing welfare state benefits, it has not analysed the case of a UBI. Using the eighth wave of the European Social Survey (ESS), this article seeks to remedy this gap by analysing individual support for a UBI in 21 European countries. The findings from logistic regression analyses with country fixed effects are partly consistent with the expectations of previous social policy and political economy literatures. Younger, low-income, left-leaning individuals and the unemployed are more likely to support a UBI. Individuals with positive views of benefit recipients and/or high trust in political institutions are also more supportive, while anti-immigration attitudes are associated with lower support. By contrast, the patterns across occupations are mixed and male respondents appear slightly more supportive. Trade union membership is not statistically significant, perhaps because of contradictory effects: unions typically support new welfare state policies but they also have a key role in many existing welfare state schemes and may worry about individuals’ attachment to the labour market. At the cross-national level, support tends to be higher where benefit activation is more pronounced and unemployment benefits less generous. These results suggest one possible reason why countries with high support for a UBI have not introduced it: the mixed support among the left means a pro-UBI coalition has to draw on right-wing voters who may support it only with lower taxes and/or extensive replacement of welfare state benefits, which in turn may further alienate parts of the left.