Green nanotechnology has progressed at a revolutionary pace thanks to biopolymers-based carbon nanomaterials. Fabrication of eco-friendly carbonized polymeric nanocomposites is an emerging research arena with numerous applications. Nano-biopolymer composites can be produced on a large scale by preparing nanoscale derivatives of polymers such as cellulose, lignin, starch, and dextran. In contrast to synthetic polymers, which can be made from petrochemical or chemical industrial processes, biopolymers are derived from biomass, plant and living organisms, which are renewable resources. These materials offer viable substitutes for environmentally problematic non-biodegradable plastics. This chapter highlights the main sources of natural and synthesitic polymers and biopolymers and their classifications. It also summarizes recent studies on the synthesis of biopolymers-based carbon and their applications in environmental, biomedical, and energy fields.