<p>International organizations (IOs) face unprecedented attacks on their legitimacy and authority from hostile domestic publics. Yet modern communication channels like social media allow IOs to interface directly with the public, offering a potential opportunity to enhance their reputations. We investigate the communication strategies IOs adopt to shore up public support in the wake of populist challenges and whether such messages are effective. We argue that IO efforts to highlight their ties to ordinary people increase engagement and political support from public audiences. To test our hypothesis, we use novel Twitter (now X) data from 2012-2022 paired with an original survey experiment of U.S. citizens that manipulates whether IOs are portrayed as technocratic or populist-friendly organizations. Our findings suggest that rhetorical style shapes which dimensions of IO support are mobilized: populist appeals generate political and distributive support, while technocratic appeals reinforce perceptions of competence. Our results highlight IOs’ agency in the social media age and suggest that they possess informational tools to blunt populist opposition.</p>