Ageism is the most prevalent form of prejudice and is experienced by both older and younger people. Little is known about whether these experiences are interdependent or have common origins. We analyze data from 8,117 older (aged 70 and over) and 11,647 younger respondents (15-29 years) in representative samples from 29 countries in the European Social Survey. Using multilevel structural equation modeling, we test the hypothesis that older people are less likely, and younger people more likely, to suffer age discrimination if they live in a country with stronger structural support for older people. We also test the hypothesis that although stronger social norm against age discrimination reduce age discrimination suffered by older people it does not inhibit discrimination against younger people. These hypotheses are supported, and the results underline the neglected problem of ageism toward youth. Findings highlight that strategies for reducing age prejudice must address ageism as a multigenerational challenge, requiring attention to intergenerational cohesion and resource distribution between ages.