​This study examines the electrical conductivity of polyethylene oxide (PEO) nanocomposite films with varying aluminum nanoparticle (AlNP) volume fractions. A sharp increase in the electrical conductivity occurs at the percolation threshold, reaching 219 S cm−1, followed by a plateau at higher AlNP concentrations, indicating the formation of stable conductive pathways. Upon UV irradiation, the electrical conductivity increases to 1770 S cm−1, suggesting the significant influence of localized surface plasmon resonance (LSPR) effects. The conductivity behavior is quantitatively characterized through mathematical modeling, highlighting the volume fraction dependence of the nanocomposite's electrical properties. Scanning electron microscopy and atomic force microscopy demonstrate the distribution and morphology of AlNPs, showing their dispersion at lower concentrations and agglomeration at higher concentrations. Fourier-transform infrared spectroscopy identifies the chemical interactions between PEO and AlNPs, while X-ray diffraction (XRD) demonstrates the AlNP-induced disruption of PEO crystallinity. These insights provide a comprehensive understanding of the nanocomposite's electrical behavior, offering valuable guidance for the design and optimization of materials for electronics and optoelectronics applications.​