‘Post-truth politics’, particularly as manifested in ‘fake news’ spread by countermedia, is claimed to be endemic to contemporary populism. I argue that the relationship between knowledge and populism needs a more nuanced analysis. Many have noted that populism valorises ‘common sense’ over expertise. But another populist strategy is counterknowledge, proposing politically charged alternative knowledge authorities in the stead of established ones. I analyse countermedia in Finland, where they have played a part in the rise of right-wing populism, using a combination of computational and interpretive methods. In my data, right-wing populists advocate counterknowledge; they profess belief in truth achievable by inquiry, not by mainstream experts but alternative ones. This is a different knowledge orientation from the valorisation of ‘common sense’, and there is reason to believe it is somewhat specific to contemporary right-wing anti-immigration populism. Populism’s epistemologies are multifaceted but often absolutist, as is populism’s relationship to power and democracy.