Sustainability transitions research lacks a crucial perspective: the spatial dimension. The interrelations between space and sustainability transition processes are thus underexposed. The spatial dimension is, of course, implicitly addressed in transition research but it often remains unclear which spatial concept is used and how the spatial conditions are embedded in the transition processes. This paper approaches the problem in two steps: (1) analysing the various understandings of transitions research and their implications for different spatial concepts relating to spatial sustainability transition; and (2) focusing on different spatial concepts (from a positivist mode to relational and socio-cultural approaches) and their reflections in different disciplines of social, natural and technical sciences as well as in practice. By identifying the links between sustainable transition approaches on the one hand and spatial conceptualizations on the other hand, this paper aims at deepening both the spatial perspective and the understanding of sustainable transition research. The results of this paper are three conceptual perspectives wherein space or spatial conceptualizations can provide added value for sustainability transition research in inter- and transdisciplinary modes. These three perspectives include (1) space as a "bridging concept," (2) space as a "normative concept," and (3) space as an "approach to action.".