Trust is the social glue that holds society together. The academic consensus is that trust is weaker among lower-class individuals and in unequal regions/countries, which is often considered a threat to a healthy society. However, existing studies are inconsistent and have two limitations: (i) variability in the measurement of social class and (ii) small numbers of higher level units (regions/countries). We addressed these problems using large-scale (cross-)national representative surveys (encompassing 560,000+ participants from 1,500+ regional/national units). Multilevel analysis led to two consistent sets of findings. First, the effects of social class on social trust were systematically positive, whereas the effects on institutional trust depended on the way social class was measured. Second, the effects of income inequality on social and institutional trust were systematically nonsignificant and smaller than the smallest negative effect of interest. Our findings suggest that researchers need to update their knowledge: social class—not income inequality—predicts trust.