The World Scientific Reference of Hybrid Materials is a set of 3 volumes, which covers the fascinating area of materials science at the intersection between purely polymeric, organic or inorganic materials. The rapidly developing research on hybrid materials is largely driven by the steadily increasing need of multifunctional materials in various branches of technology. However, much of the research is also driven by the curiosity of the researchers and the long lasting wish to merge the most beneficial properties of the various materials into one. The flexibility of polymers could, for example, be merged with the electronic conductivity of metals or the mechanical resistance of ceramics, which will be of great value for the industries. This reference covers the areas of synthesis of such hybrid materials, which take benefit from each of the consisting ingredients, and overviews some of the emerging applications based on the materials. Much of the current research is still in its infancy, but hybrid materials are already now considered to be the key enabler for important future developments, for example flexible electronics. With this perspective, this reference aims at giving the general public an overview over the topics of relevance in this field, but also attracting new researchers to this intriguing scientific area.