In light of the growing environmental and economic challenges associated with the linear economy model (based on the extract–produce–dispose pattern), circular strategies focusing on the efficient use of resources, reuse, and waste management are becoming increasingly important. Within this framework, edible films and coatings emerge as a viable substitute for traditional packaging materials, particularly in relation to circular economy principles and the zero-waste approach. This chapter examines recent scientific developments and novel strategies involving the utilization of agri-food by-products in the formulation of environmentally sustainable edible films and coatings. The potential of waste materials, both plant and animal, as sources of biopolymers (including cellulose, starch, pectins, alginates, carrageenans, agar, chitosan, whey proteins, and waxes) used to develop sustainable packaging matrices is discussed. Furthermore, the role of these raw materials as sources of functional additives that significantly influence the performance of finished materials is highlighted. The chapter emphasizes the potential for aligning waste management practices with the development of innovative, biodegradable packaging solutions that contribute to a more sustainable food system and minimize the environmental footprint of packaging.