In Western Europe, rightwing populist parties and their supporters frequently deny the realities of climate change and oppose climate policies. Meanwhile, public opinion research has tied ideological orientations associated with rightwing populism to climate change denial/ skepticism and climate policy opposition. Yet, comprehensive studies assessing the relative importance of various rightwing populist orientations across national contexts are lacking. Using European Social Survey data (Round 8) from 15 Western European countries, we systematically investigate the relationships between a large set of orientations related to rightwing populism and public views about climate change. The results show that nationalism and nativism, that is, orientations associated with the thick ideology of rightwing populism, appear to be comparably strong and consistent predictors, especially regarding opposition to climate change mitigation policies. However, the relative importance of different orientations varies across Western European countries, and depend on whether the focus is on policy attitudes or climate change beliefs. Researchers studying single countries and/or specific attitudinal outcomes should therefore be cautious when generalizing about these relationships cross-nationally.