Chitosan is a derivative of chitin, acquired as a by-product of processing and handling of fishes and crustaceans. Due to these unique properties, it has various applications in biological and technological research areas. Chitosan is an appealing bio-polymer for the packaging and preservation of food. It possesses antibacterial activity and film-forming properties and can be applied through coating, dipping, spraying, or wrapping in the form of films. This chapter covers various properties of chitosan and its functionalities. Also, chitosan blends and nanocomposites, production applications, and techniques for extending the shelf life of meat, and fish products have also been discussed. Rapid growth is being seen in the demand for safe, wholesome food that uses as few artificial ingredients as possible. Due to the environmental hazards of plastic polymers, much effort has been made to substitute several synthetic plastic packaging materials using bio-based polymers. The current chapter relates to the knowledge of chitosan films in biodegradable and sustainable food preservation and packaging.