Many integration theories predict that heightened integration in Europe will give rise to a European identity. As integration advances, so does the scholarly debate on identity. This article endeavours to contribute to the debate by investigating the relationship between European integration and European identity longitudinally in 14 countries over 21 years from 1992 to 2012. Using Eurobarometer and EU Index data, this relationship is found to be exponential with current integration levels predicting the imminent emergence of a European identity. In order to better understand whose identities are impacted or formed most by integration, the paper then turns to three intervening concepts: (1) cognitive mobilization, (2) optimism, and (3) support of the EU. All of these amplify the effect of integration on identity with the noteworthy exception of optimism. Finally, the article evaluates the implications of these findings for neofunctionalism and the literature on European identity more broadly.