Increasingly, research on attitudes towards the European project focuses on transnational practices. This article furthers the transnational approach by offering the first systematic analysis of how domestic transnationalism – i.e. transnational practices conducted in the home country – influences the formation of pro-European sentiments. We argue that domestic transnational activities foster recognition of common, transnational interests and identities that support the European integration project. Using a 2013 Eurobarometer, we show the distinct need to pay attention to domestic transnationalism. Individuals engaging in more domestic transnational activities display more pro-European sentiments in four of our five dependent variables. Moreover, the effect of domestic transnationalism is particularly intense among less-educated citizens.