The current work deals with the synthesis and characterization of strontium titanate (SrTiO3) nanoparticles reinforced polyvinyl chloride (PVC) and polyvinylidene fluoride (PVDF) blend nanocomposite films prepared via a solution casting approach. The structural, thermal, morphological characteristics of the PVC/PVDF/SrTiO3 nanocomposite films were explored through Fourier transform infrared spectroscopy- FTIR, X-ray diffraction–XRD, thermogravimetric analysis–TGA, scanning electron microscopy–SEM and atomic force microscopy–AFM. The electromagnetic interference (EMI) shielding efficiency (SE) of the PVC/PVDF/SrTiO3 nanocomposite films were investigated in Ku-band (12–18 GHz). The EMI shielding result demonstrated the enhancement in EMI SE values with an increase in the SrTiO3 loading. The PVC/PVDF/SrTiO3 nanocomposite exhibits the maximum EMI SE values ∼ − 12.51 dB at 10 wt% of SrTiO3 loading. These findings affirm the dominating absorption behaviour of the nanocomposite (73.9%) with an overall shielding ability of 99.6% and negligible transmittance. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.