The development and utilization of polymeric blends and nanocomposites for different applications have improved in recent years due to the investigations, synthesis, and addition of novel, improved, and modified nanofillers toward polymeric matrix amelioration and imbuing polymer nanocomposites with special functionalized properties. The resulting nanocomposites usually show superiority to their neat and uncombined counterparts in one or a combination of new properties. These include but are not limited to, improvement in mechanical and optical properties, electrical and thermal superiority, and physical as well as biological advantages. Nanofillers present unique opportunities and a wide spectrum for the synthesis of highly functionalized materials for targeted applications. They also present environmentally friendly alternatives for different industrial applications. In this chapter, the recent developments in the field of nanofillers, novel material explorations, unique nanofiller blends, the progress made in their synthesis and applications, as well as their shortcomings, are explored. In addition, different sections of this work involving the different synthesis techniques, characterizations, structures, functionality, and applications of nanofillers are discussed in this chapter. Nanofillers and their different fields of applications are also presented and discussed in the scope of this chapter. Overall, the intricacies of the recent developments in nanofiller technology and their inherent applications are covered in this scope.