Biopolymers and bioplastics have emerged as essential materials in the transition toward a circular and sustainable economy. Derived from renewable biological sources such as plants, microbes, algae, and agricultural waste, these polymers offer alternatives to petroleum-based plastics, which have long contributed to environmental degradation and pollution. Biopolymers include natural macromolecules such as polysaccharides, proteins, and polyesters, while bioplastics are polymer materials that are either bio-based, biodegradable, or both. Their production methods vary widely depending on feedstock and desired material properties, ranging from the extraction of natural polymers like starch and cellulose to advanced microbial fermentation processes that create polyhydroxyalkanoates (PHAs). Another major bioplastic, polylactic acid (PLA), is produced by fermenting sugars from corn or sugarcane into lactic acid, followed by polymerization. Applications for biopolymers span across packaging, agriculture, consumer products, engineering materials, and biomedicine. Packaging remains the largest market, where biodegradable materials such as PLA, thermoplastic starch, and cellulose derivatives provide compostable alternatives to single-use plastics. In agriculture, biodegradable mulch films and controlled-release fertilizer carriers reduce waste and environmental contamination. In medicine, biopolymers’ biocompatibility allows them to be used in sutures, implants, drug delivery systems, and tissue engineering scaffolds. Additional applications include textiles, automotive components, building materials, and emerging fields such as biofabrication and regenerative materials. Despite their environmental advantages, biopolymers face challenges including higher production costs, limited industrial composting infrastructure, and competition with food crops for land use. Some bioplastics require specific conditions to degrade, making disposal systems critical. Research efforts focus on improving mechanical strength, reducing costs, utilizing non-food feedstocks, and improving recycling technologies. As innovation accelerates and regulatory pressure increases, biopolymers and bioplastics are expected to play a central role in replacing traditional plastics and supporting global sustainability goals.