Regions tend to become the relevant space for the analysis of public funding of innovation, as emphasised by numerous recent works. However, it is still to be demonstrated that the regional level is really the right spatial scaling for implementing innovation public policies. The aim of this paper is to provide a series of analytical and empirical elements that could help clarify this issue. The paper builds first on a review of the literature dedicated to territorial innovation systems (TIS), showing that beyond their extreme diversity, there are several criteria that provide a basis for a tentative typology of TIS. We then examine how and on which grounds there has been a shift of focus from the notion of National Innovation System (NIS) to that of Regional Innovation System (RIS). The paper also provides a rationale for considering the region as being at the core of TIS, but as part of a multiscalar and dynamic territorial setting. Building on these analytical grounds, the paper turns to an empirical investigation based on the French innovation system case. The specific features of this system and its recent evolution towards more regionalisation display particular patterns of how public policies, and more specifically regional policies, play a nodal role in initiating, supporting and coordinating innovation processes and projects at the regional level. But the leveraging effects of theses policies on territorial innovation dynamics are subject to various contingent conditions related both to the funding mechanisms mobilised and to the timing of the support to innovation projects according to their development stages. We conclude the paper by identifying some crucial pending issues and suggesting directions for further investigation on the role of regional innovation policies in various territorial and sectoral contexts.