Recently, nanofillers have received great attention due to their versatile characteristics-especially those based on carbon nanotubes and clays. Nanographene platelets and montmorillonite clay are communal examples of one-dimensional (1D) nanoparticles. The well-known definition of nanofillers is that they must have at least 1D in the range between 1 and 100 nm and the others should be bigger than 100 nm. They are generally in the form of sheets of 1 nm to a few nanometers thick to hundreds and thousands of nanometers long. Nanofillers as a group are barely considered unique anymore, meanwhile, various products hold them but they still attract innovative research, particularly in the area of graphene and further carbon-related fillers. Nanofillers can be categorized into three types: one nanoscale dimension (nanoplatelet), two nanoscale dimension (nanofiber), and three nanoscale dimension (nanoparticulate). The advantage of such nanofillers is that they produce very good mechanical properties at low loadings, enhanced fire-resistant properties, superior barrier properties, scratch resistance, and improved heat distortion performance when compared to pristine material. The main objective of this chapter is to review the research on various types of nanofillers and their effect on the structural, morphological, and optical properties of pristine base materials and also its performance in various applications.