Using newly collected cross-country survey and experimental data, we investigate how beliefs about intergenerational mobility affect preferences for redistribution in five countries: France, Italy, Sweden, U.K., and U.S. Americans are more optimistic than Europeans about intergenerational mobility, and too optimistic relative to actual mobility. Our randomized treatment that shows respondents pessimistic information about mobility increases support for redistribution, mostly for equality of opportunity policies. A strong political polarization exists: Left-wing respondents are more pessimistic about intergenerational mobility, their preferences for redistribution are correlated with their mobility perceptions, and they respond to pessimistic information by increasing support for redistribution. None of these apply to right-wing respondents, possibly because of their negative views of government.