This paper evaluates the rise of behavioral economics as a policy paradigm within EU policymaking. After presenting its key approaches and insights, it first charts how behavioral economics has filtered into EU policy. In what policy areas did it emerge and what insights were imported? It secondly maps the type of actors and organizations that were instrumental in disseminating behavioral economics. How did these actors translate theoretical insights into EU policy? It finally aims to determine to what extent behavioral insights are changing the policy outlook of the EU. How are behavioral approaches affecting the political rationality of EU policy and do they present a break with reigning (neo-)liberal policy views. The paper concludes by arguing that while behavioral approaches to EU policy remain modest, they present a formidable shift in the political rationality of EU governance with potentially far-reaching political implications.