Does supranational identity have an independent effect on individuals’ beliefs about culturally contested issues in their national systems? This article demonstrates that self-categorization in the supranational realm – a seemingly unrelated category to domestic value cleavages – has implications for individuals’ views on cultural issues. Traditional theories of international norm diffusion focus almost exclusively on state-level interactions, but our findings provide further evidence to the existence of a more direct mechanism through which norms reach some citizens. A sense of identification with a supranational entity such as Europe makes citizens more likely to espouse the views and opinions promoted by supranational organizations. We use the European Values Study to examine whether supranational identity is associated with socially liberal preferences. Results from the multi-level models indicate that supranational identity exerts a systematic effect on attitudes toward lesbian, gay, bisexual, and transgender rights and gender equality. Additionally, while these effects are more consistent in EU member states, supranational identity exhibits a similar impact on social attitudes in non-EU countries such as those in the former Soviet Union.