Literature on representative bureaucracy has been mainly focused on examining passive and active representation of public servants. However, the analysis of bureaucratic representativeness in independent regulatory agencies is an under explored aspect. The claim that regulatory agencies have been created as expert bodies may raise debates about the extent to which these bodies should reflect the society they serve, in particular, in policy topics that are highly specialized. Our study seeks to examine representativeness of (regulatory) agencies that belong to different policy domains, and to provide evidence on the implications of such representation in core aspects on their perceived performance. To do this, we examine representative bureaucracy of EU agencies and national agencies in the sectors of food safety, data protection and finance in six countries (Belgium, Denmark, Israel, Germany, Spain, and Switzerland). Our empirical analysis relies on a biographical dataset of socio-demographic and professional characteristics of public officials working in these agencies, and also on interviews targeted to core actors of the sectors examined