Active packaging material has been used in the food industry to maintain the quality of packaged foods. The use of conventional polymers has serious environmental consequences due to improper disposal or recycling methods. Therefore, active packaging films based on biopolymers have been developed due to their excellent biocompatibility, degradability, and eco-friendliness. Amongst all essential oils, grape seed oil is considered to be a promising antimicrobial agent. It comprises large quantities of flavonoids, tocopherols, and other antimicrobial compounds. Grape seed essential oil has good antimicrobial and antioxidant activity. As a film, it is used to preserve food items such as poultry products, fish, and tomatoes. This work aimed to develop a polybutylene adipate terephthalate (PBAT) biocomposite film incorporated with natural grape seed essential oil (GEO) in addition to silica nanoparticles (SiO2 NPs) using the solution casting process. To achieve the desired packaging properties of the prepared PBAT-based film, the concentrations of grape seed essential oil as a plasticizer and nanosilica as a filler material were varied. The optical, physical, barrier, mechanical, surface hydrophobicity, and antibacterial properties of the PBAT/GEO/SiO2NP films were assessed. The FT-IR and XRD results indicated that GEO had effective miscibility with the PBAT/SiO2NP matrix. The addition of GEO increased the film flexibility, opacity, and antimicrobial activity, but the incorporation of SiO2NPs in the PBAT/GEO blend increased the tensile strength, thermal stability, and antimicrobial activities. The PBAT/GEO/SiO2NP films exhibited excellent antibacterial activity against food spoilage microorganisms. Finally, due to improved antimicrobial activities, film flexibility, optical, and heat resistance properties, the PBAT/GEO/NP nanocomposite films were found to have high potential for usage in active food packaging applications.