Electoral disinformation is feared to variously undermine democratic trust by inflaming incorrect negative beliefs about the fairness of elections, or to shore up dictators by creating falsely positive ones. Recent studies of political misperceptions, however, suggest that disinformation has at best minimal effects on beliefs. In this article, we investigate the drivers of public perceptions and misperceptions of election fairness. We build on theories of rational belief updating and motivated reasoning, and link public opinion data from 82 national elections with expert survey data on disinformation and de facto electoral integrity. We show that, overall, people arrive at largely accurate perceptions, but that disinformation campaigns are indeed associated with less accurate and more polarized beliefs about election fairness. This contributes a cross-nationally comparative perspective to studies of (dis)information processing and belief updating, as well as attitude formation and trust surrounding highly salient political institutions such as elections.