A novel technique called active food packaging (AP) offers the food sector a new method of food preservation. The need for AP is expanding as a result of market developments and consumer demands, which motivates researchers and the food industry. AP applications have been significantly impacted by the development of nanotechnology as a result of its unique physicochemical and biological characteristics. Biopolymers’ thermal, mechanical, gas barrier, and composability qualities have been considerably enhanced by the integration of nanoscale elements into the polymer matrix, eliminating the drawbacks of bio-based film packaging. Due to growing customer desire for less processed and preservative-free meals, AP is essential nowadays. Additionally, there is increased interest in renewable biopolymer materials in the packaging system due to growing concerns about usage of synthetic non-biodegradable polymers. The current state of functional films made from sustainable biopolymers and different antimicrobial nanofillers for use in active food packaging is thoroughly covered in this chapter. Preservatives are avoided when these nanofillers are used directly in packing materials. The biopolymers, which mostly consist of polysaccharides, proteins, and synthetic polyesters, are derived from a variety of sources, such as plants, animals, or microorganisms. Additionally, a thorough discussion of the antimicrobial nanofillers employed in the creation of bio-based composites is provided. Also outlined is the most current development in the use of various biopolymeric nanocomposites in antimicrobial food packaging. Finally, it is also claimed that there are safety concerns regarding the use of bio-based nanocomposite.