National policy makers have shown a growing interest in the regional dimension of innovation processes, and regional policy makers are seeking to promote their own competitiveness by supporting innovation. To advance the OECD quantitative research on regions and innovation, a categorisation of regions was developed using socio-demographic, economic, and innovation-related variables. Many different categorisations are possible depending on the purpose of the peer group comparisons. This categorisation was developed with the main goal of highlighting the diversity of regional profiles across OECD regions. Similar types of analysis have been performed with regions of the European Union. This analysis identifies eight groups of regions based on the similarity of their performance on the 12 variables used in the statistical cluster analysis. These eight groups were then classified into three macro categories based on relevance for policy recommendations. Possibilities for further research to develop different forms of regional peer groupings are discussed.