This paper presents the suitability of polyaniline/zinc tungstate (PANI/ ZnWO4) nanocomposites with tunable electrical properties for a range of multifunctional applications. In-situ oxidative polymerization method was employed to synthesize the PANI/ZnWO4 nanocomposites with different mass percentages of the dispersant ZnWO4 (10%, 20%, 30%, and 40%). The structural features of the samples were analyzed using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy, and Raman spectroscopy techniques. Frequency-dependent electrical conductivity studies and dielectric responses were investigated for PANI/ZnWO4 nanocomposites in the range of 100 Hz - 1 MHz. PANI/ZnWO4 nanocomposites showed tunability in the observed high dielectric constant owing to the conductivity relaxation with varying dispersant concentrations. The electromagnetic interference shielding effectiveness (EMI-SE) of the PANI/ZnWO4 nanocomposites were found to be increased from -14 dB to -21 dB with enhancing wt% of ZnWO4 in the PANI matrix. The composite samples displayed practically relevant shielding effectiveness in the entire microwave, Xband covering 8 to 12 GHz. The overall attenuation of the incident EM energy was around 99%, which is highly suitable for diverse EMI shielding applications. The nature of mild steel (MS) metal corrosion in 5 M HCl solution in the unprotected and protected system was studied by using SEM, AC impedance spectroscopy, potentiodynamic polarization (Tafel plots), and atomic absorption spectroscopy (AAS) techniques. The preliminary results indicate the mixed-type anticorrosion behavior. The AAS, AC impedance spectroscopy, and SEM results support the potentiodynamic polarization results.