Following the 2020 general election, Republican elected officials, including thenPresident Donald Trump, promoted conspiracy theories claiming that Joe Biden’s close victory in Georgia was fraudulent. Extant literature suggests multiple hypotheses regarding effects these conspiracy theories could have had on Republican turnout in the Senate runoff elections that took place the following January. Conspiracies regarding rigged elections could signal that voting doesn’t matter, lowering adherents’ external efficacy and decreasing their likelihood of voting relative to otherwise similar nonadherents. Conspiracy theories could also stoke political anger at out-partisans, which would predict heightened commitment to voting as a means to address the threat posed by political opponents’ supposed election theft. We test these hypotheses by combining behavioral measures of engagement with election conspiracies and administrative data on voter turnout at the individual level by linking the accounts of 40,000 Twitter users in Georgia to the voter file. We find limited turnout effects – liking or sharing retweets opposed to conspiracy theories was associated with higher turnout in the runoff election and, among more active users, those who liked or shared tweets promoting fraud-related conspiracy theories were less likely to vote.