Nanofillers, also known as nanoparticles or nanomaterials, have revolutionized various industries by offering unique properties and opening up new possibilities for technological advancements. This manuscript explores the thermal properties of nanofillers and their influence on matrix materials. Incorporating nanofillers into polymers, ceramics, metals, and composites has led to unprecedented enhancements in mechanical, thermal, and electrical properties. These advancements have enabled the development of advanced structural components, flexible electronics, and energy storage devices. The manuscript highlights the significance of nanofillers in improving thermal resistance and energy efficiency in materials for high-temperature environments. Furthermore, role of nanofillers in thermal interface materials (TIMs) for efficient heat dissipation in electronic devices. This chapter provides insights into the specific heat and thermal conductivity of various nanofillers, highlighting the impact of particle size, shape, and density on their thermal properties. The measurement techniques, such as differential scanning calorimetry (DSC), guarded hot plate method, transient hot-wire technique, and transient plane source method, are discussed to accurately determine specific heat and thermal conductivity values.