Social networking sites offer politicians an opportunity to mobilize followers through carefully crafted messages appealing to their emotions. We examine the effects of uncivil and post-truth communication of populist and non-populist party leaders on the emotional emoji reactions of social media users during the COVID-19 pandemic crisis. Conveying a disrespectful tone toward the participants and topics of the debate, lying accusations, and incivility have become prominent aspects of contemporary political discourse in many European countries. We combine research on emotional cues in online political communication and the effects of political elites’ messages on social media. We apply manual content analysis (N = 2,549 posts) to study the political communication of Czech political party leaders on Facebook during the COVID-19 pandemic (March 2020 to February 2021), which generated a higher sense of threat and uncertainty in the public. We show that uncivil and post-truth message elements, affiliation with a populist party, and pandemic influenced the volume of emotional interactions with political posts. The article has important implications for the study of how incivility and attacks on truthfulness can influence opinion exchange in public debate or increase societal polarization.