Inclusions of nanosized ceramic particles in a polymer matrix influence the dielectric properties of their composite more when compared to conventional microcomposites through a greater interfacial contact area between the filler particles and the polymer per volume. This review summarizes the research of and potential for polymer-ceramic nanocomposite use as electrostatic energy storage materials. a particular focus is made on the role of the interfacial region, properties and characterizations, and the significance of controlling the nanofiller surface for improving the energy storage capacity by nanocomposite dielectric capacitor films. Various types of surface modifications and methodologies that have been applied to ceramic nanofillers in an effort to control dielectric properties of the polymer nanocomposites are reviewed. Special mention is made of new structure-property-relationships at the interface through altering the chemical and electronic nature of the particle-polymer interface. Recent research results suggest that ligands, as a function of their electron density influence at the filler surface, reduce filler surface conductivity to maximize the dielectric energy storage density while reducing dielectric losses. the article concludes by briefly revisiting theoretical models of the filler-polymer interface structure property as an influence on properties of polymer-ceramic nanocomposite dielectrics.