<p><em>The present study reports the green synthesis of bismuth ferrite (BFO) nanoparticles using Moringa oleifera leaf extract and their incorporation as nanofillers in a polymer membrane consisting of polyvinyl alcohol (PVA) and polyaniline (PANI) for potential electrochemical device applications. The PVA-PANI-BFO membrane was prepared using a solution cast technique, and the synthesised nanoparticles and the membrane were characterised using various spectroscopic techniques. X-ray diffractometry (XRD) confirmed the BiFeO3 phase of the synthesised BFO nanoparticles, and the Raman spectrum exhibited characteristic BFO bands. Fourier-transform infrared spectroscopy (FTIR) revealed that the synthesised BFO nanoparticles contained functional groups of phytochemicals. Field emission scanning electron microscopy (FESEM) was used to characterise the surface structure of the synthesised membranes. The ionic conductivities of the synthesised membranes were found to vary with relative humidity (RH). The PVA-PANI-BFO membrane was found to be more stable against moisture and exhibited reduced ionic conductivity as compared to the PVA-PANI membrane. This work demonstrates the potential of green synthesis approaches for nanoparticle synthesis and highlights the effect of BFO nanoparticles on the ionic conductivity of the polymer membrane, which could have important implications for electrochemical devices. </em></p>