Many countries worldwide have seen populist resentment against scientists, which can manifest as “science-related populist attitudes” among the population. These attitudes can be assumed to divide populations into multiple segments—each endorsing or rejecting different facets of science-related populism, with segment sizes and characteristics varying between countries and cultural contexts. This study tests this with a secondary analysis of four public opinion surveys from Austria, Germany, Switzerland, and Taiwan (total N = 4598), combining a Most Similar Systems Design (MSSD) and a Most Different Systems Design (MDSD). It uses fixed-effects latent class analysis to demonstrate that Austrian, German, Swiss, and Taiwanese publics can be grouped into three segments: Full-Fledged Populists, People-Centric Non-Populists, and Deferent Anti-Populists. A large majority in all countries can be classified as Non-Populist or Anti-Populists, whereas Populists, who support the entire spectrum of science-related populism, make up the smallest segment. Bayesian regression shows that Populists are older and more likely to support right-leaning political views. Cross-country and cross-cultural comparisons reveal differences in segment sizes and characteristics: For example, Populists are more prevalent in Austria, while Germany has a large proportion of Anti-Populists. These are less widespread in Taiwan, where Non-Populists form a particularly big segment. The findings can be explained with national political, cultural, and historical contexts to some degree. Eventually, they are discussed against the backdrop implications for science communication and future scholarship on public science skepticism.