This chapter explores the potential roles that business, innovation, knowledge, and entrepreneurial ecosystems take to enable sustainability transitions. This conceptual research is an explorative study that shows initial research on the relation between different ecosystem types and elements of sustainability transitions. By using the socio-technical transition literature, we shed light on how the four ecosystem types influence the dynamics between niche-innovations and the dominant regime. These dynamics influence the occurrence of sustainability transitions. The research is based on a literature review of various strands of literature that have been combined in a number of propositions. Each of these propositions offers valuable future research directions. The findings shed light on the importance for firms and policymakers to combine different ecosystem types to stimulate socio-technological niche-innovations to grow into new dominant regimes or influence the development directions of the existing regime. We discuss how policy makers and companies have to be aware that each ecosystem type has its unique characteristics and theoretical foundations, and therefore influences different elements of sustainability transitions. Our findings have important implications for future studies of ecosystem concept definitions and characteristics, ecosystem research contexts, and the interrelation with other literature streams.