Many EU/EEA countries have applied behavioural and social science capacities (“Behavioural Insights”) to provide recommendations for decision-makers for the planning of actions, policies and communications in response to COVID-19. Based on interviews with 11 experts working in the area of behavioural insights for public health in four EU member states with different administrative systems (Slovenia, Italy, Spain, Portugal) this project aimed to (1) explore good practices in establishing and maintaining effective national BI capacities and infrastructures in public health; (2) identify barriers and facilitators to the implementation of BI within the administrative systems of the countries considered; and (3) explore how to provide support in retaining and institutionalising BI expertise created during the COVID-19 pandemic. Interviewees perceived the BI teams and activities in their respective countries to be in the early stage of development, either in the phase of initiation or adoption. Based on the input by participants, we emphasize the need to increase awareness regarding the relevance of BI for public health questions and making BI an integral discipline in public health institutions and policy making. The contributions that are possible within the European Union structures to further encourage this process include furthering the connection between experts and stakeholders, developing European wide knowledge platforms, competence centres and training activities, advocating for and supporting global resolutions, financing pilot projects and research that further explores the different infrastructures for an effective integration of BI in public health systems.