Novel multiferroic nanocomposite fabricated by Ni–Zn–Cu-ferrite (NZCF)-mullite is reported in this article. The crystallographic phases are confirmed by X-ray diffraction. The static magnetic properties are measured for both bare NZCF and mullite encapsulated NZCF nanocomposite which show the successful retention of the magnetic behaviors of the nanocomposites even at higher annealing temperature of 1200 °C. The dielectric response is estimated and high value of dielectric constant (∼210.7 at 100 Hz) is observed for the mullite encapsulated NZCF nanocomposite due to the formation of interfacial polarization in the nanocomposite. The temperature dependent dielectric response suggests the presence of dielectric polarization in the NZCF-mullite nanocomposite. Magnetocapacitance (MC) study of the NZCF-mullite nanocomposite sample is observed at room temperature (RT). The observed MC and its variation with magnetic field confirm the presence of strong interactions between the magnetic and ferroelectric order parameters in the nanocomposite sample.