Enhancing the opto‐electrical properties of polymer is crucial for optoelectronic devices. This study emphasis the synthesis of strontium titanate (SrTiO3) nanoparticles using a green sol–gel method and incorporates them into polyvinyl chloride (PVC) to create nanocomposite films via solution casting. The structural, optical, thermal, and electrical properties of PVC with SrTiO3 at concentrations of 1, 3, and 5 wt.% were examined. Better crystallinity was obtained with filler incorporation. Fourier transform infrared shows the physical interaction between nanofiller and the matrix. SEM results suggested that SrTiO3 nanofiller are well distributed in PVC surface. UV–Vis spectroscopy was used to study optical behavior of the nanocomposites. Optical bandgap energy decreased from 3.2 to 2.5 eV with increased concentration of SrTiO3 in PVC matrix. Photoluminescence results show the reduction of electron hole recombination rate. The integration of SrTiO3 nanofiller into the PVC matrix improved the thermal stability, dielectric constant, and the overall performance of the prepared nanocomposite films, making them suitable for high‐temperature optoelectronic and energy storage applications. The green synthesis of SrTiO3 nanofiller also ensures the environmental benefits, high purity, and homogeneity, leading to consistent enhancements in the PVC/SrTiO3 composites. These improvements highlight their potential for advanced optoelectronic devices requiring efficient and durable materials.