The present study aimed to access the influence of starch nanocrystals (SNCs) with chitosan on functionality of gluten-based bionanocomposite films. Films were reinforced with SNCs (1, 2, and 3 %) along with chitosan (1.5 % and 2.5 %) and characterized for their functional, barrier, morphological, biodegradable, and antimicrobial properties. Results showed that water absorption capacity, solubility, and water vapour transmission rate were significantly (P < 0.05) reduced with the incorporation of SNCs and chitosan, however, highest tensile strength (40.82 MPa) and elongation at break (31.09 %) were observed in 2 % of SNCs and 2.5 % of chitosan. The multifunctional films have high opacity (lightness value >90) confirming with higher thickness (0.17–0.22 mm) of films. X-ray diffraction studies interpret no significant change in A-type crystallinity of the base biopolymer. Field emission scanning electron microscopy showed that bionanocomposite films have fewer surface cracks, less configuration, and crystallinity changes in the composite structure of biopolymer. Fourier transform infrared spectra revealed no differences in the bands, suggesting a positive molecular association confirming the synergistic effect of polyvinyl alcohol (PVOH) and SNCs on gluten in comparison to control film. However, chitosan in films enhanced antioxidant and antimicrobial properties, showing 13.05 mm and 16.66 mm of a zone of inhibition against Staphylococcus aureus and Escherichia coli, respectively. Furthermore, all films showed noticeable degradation >95 % within 55 days under soil conditions. In summary, the addition of SNCs and chitosan produced a stronger/antibacterial film comparable to plastic films for commercialized food packaging industries.