<p>This study explores the enhancement of dielectric, thermal, and structural properties of chitosan-polyvinyl alcohol (CS-PVA) nanocomposites through the incorporation of zirconium cerium oxide (ZrCeO₄) nanoparticles (NPs) and subsequent gamma irradiation treatments. A series of ZrCeO₄NPs/CS-PVA films were prepared via solution casting with varying nanoparticle concentrations (1%, 2%, and 3% by weight) and irradiated at gamma doses of 5, 15, and 25&#xa0;kGy. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed strong interfacial interactions and modifications in the crystalline structure of the CS-PVA matrix upon nanoparticle additions. Scanning electron microscopy (SEM) demonstrated homogeneous dispersion of ZrCeO₄NPs within the matrix, leading to a denser structure and smoother surface morphology at higher nanoparticle concentrations. Thermogravimetric analysis (TGA) revealed improved thermal stability with increasing ZrCeO₄NPs contents, indicating enhanced material resistance to decomposition. Dielectric measurements showed that the real part of the dielectric constant (<i>ε</i>') significantly increased at lower frequencies, especially for nanocomposites irradiated at 15&#xa0;kGy, suggesting an optimal balance between interfacial polarization and matrix integrity. A marked reduction in dielectric loss (<i>ε</i>'') with increasing frequency was observed, attributed to limited dipole reorientation at higher frequencies. The relaxation time and activation energy, derived from frequency-dependent tangent loss data, demonstrated that gamma irradiation optimizes dielectric performance by modulating relaxation mechanisms within the nanocomposites. The combined effects of ZrCeO₄Nps and gamma radiation provide a novel route for tuning the dielectric properties of CS-PVA composites, making them highly suitable for advanced dielectric applications in flexible electronics, sensors, and energy storage devices.</p>