This paper discusses the current tendency of institutionalizing supranational regions and building their identities in planning. The focus is on the interplay of regional identities and branding, for regional identity and image are understood as intertwined both conceptually and in the everyday practices of region-building. Research on the Barents and Ireland–Wales supranational regions is discussed by making an analytical distinction between thick and thin region-building, emphasizing that regional identity, as an aspect of thin region-building, has a strong instrumental element and is assumed to cause positive development across borders. It is argued that as a result of the emphasis on competitiveness, marketing-oriented promotional representations are now becoming emphasized in region-building. The advocates of region-building did not emphasize thick and/or cultural identity, but they were aware that it, too, is part of European regional policy and that they should react accordingly by promoting it.