This manuscript aims to review definitions of chemical space proposed in the literature, emphasizing the approaches to generate a consensus view of the chemical space. Building upon the developments of others and our group on chemical space, also we propose the notion of chemical multiverse. After this brief introduction, we discuss the current definitions of chemical space. Section 3 introduces the concept of the chemical multiverse and compares it with the notion of consensus chemical space. The last section presents summary conclusions and an outlook.