<p>Why do people support conspiracy theories? Past works on this question have primarily centered on individual factors such as psychological characteristics and political stances. This study explores how economic inequality influences people’s support for conspiracy theories. I use the conspiracy theories related to the 2020 presidential election as a case study. After the presidential election, then-president Donald J. Trump propagated conspiracy theories on Twitter to deny the election outcome. I collected 181,314 tweets posted by 75,100 U.S. Twitter users to support Trump’s conspiracy theories. I calculated the number of users who supported Trump’s conspiracy theories per county and merged the Twitter data with county-level economic information. Multi-level regression models show that online support for election conspiracy theories is stronger in counties with a higher level of inequality. In addition, the 2020 economic crisis amplifies the effects of inequality. In counties where the economic crisis is more severe, the existing inequality exerts greater effects on online support for election conspiracy theories. A series of robustness analyses, bot detection, and placebo tests support these findings. This study sheds light on the contextual factors underlying the support for conspiracy theories and adds to our understanding of economic inequality’s social outcomes.</p>