Climate change denial tends to be prevalent among right-wing populists, but the reasons for this are not clear. This study aimed to examine the association between climate change denial and attitudinal variables associated with contemporary right-wing populism. Specifically, we focused on the mediating role of trust, or lack thereof, in climate science, as right-wing populists’ discourse on climate change tends to be centered on claims that climate science is biased and therefore unreliable. The results from an online survey (N = 232) demonstrated that climate change denial was most strongly predicted by exclusionism and anti-egalitarianism—negative attitudes towards multiculturalism, feminism, and homosexuality. This association was entirely mediated by lower trust in climate science, even while controlling for overall faith and literacy in science. Surprisingly, populist attitudes did not predict climate change denial or lower trust in climate science. This suggests that the so-called hosting ideological dimension of right-wing populism, characterized by resistance to social and cultural changes, plays a key role in this context. Moving forward, efforts to understand and engage with these ideological concerns and biases could be fruitful in addressing mistrust in climate science and ultimately climate change denial.