Regional governance has received growing attention, not only from researchers, but also from politicians and practitioners of regional development. The understanding and usage of the concept, however, are highly heterogeneous: sometimes regional governance is described or explained in terms of its characteristics, processes and impacts, while at other times, it is framed as a tool for regional development. This article develops a definition and framework for a systematic assessment of various regional governance forms. For this purpose, it draws on material from a three-round Delphi survey among practitioners and researchers who are experts of regional governance. On this basis, a consolidated definition of regional governance is proposed as ‘the vertical and horizontal coordination of regional transformation processes beyond administrative boundaries by state and non-state actors’. Furthermore, the framework identifies five dimensions of regional governance: (a) participation, (b) bindingness, (c) formalisation, (d) regional autonomy and (e) power relations. These dimensions are disaggregated into a total of 21 indicators to systematically describe and analyse different regional governance forms., Regional governance has received growing attention, not only from researchers, but also from politicians and practitioners of regional development. The understanding and usage of the concept, however, are highly heterogeneous: sometimes regional governance is described or explained in terms of its characteristics, processes and impacts, while at other times, it is framed as a tool for regional development. This article develops a definition and framework for a systematic assessment of various regional governance forms. For this purpose, it draws on material from a three-round Delphi survey among practitioners and researchers who are experts of regional governance. On this basis, a consolidated definition of regional governance is proposed as ‘the vertical and horizontal coordination of regional transformation processes beyond administrative boundaries by state and non-state actors’. Furthermore, the framework identifies five dimensions of regional governance: (a) participation, (b) bindingness, (c) formalisation, (d) regional autonomy and (e) power relations. These dimensions are disaggregated into a total of 21 indicators to systematically describe and analyse different regional governance forms.