Biopolymers materials exhibit outstanding potential in various conservation applications of historical paper manuscripts and bookbinding due to their flexible functionalization and various characteristics. This study aims to make an integrated study for the different application purposes of natural and synthetic biopolymers that can be used in the conservation of historical paper manuscripts and leather bindings. This study discussed the different sources of biopolymers such as plants, animals, and microorganism sources. The different applications of biopolymers such as consolidation, adhesive, retanning, cleaning, gap filling, and lubrication, antifungal were explained. The chemical composition, advantages, disadvantages, and application techniques of biopolymers were also discussed. This study showed that there are many biopolymers used in the field of treatment of paper manuscripts and leather binding. Still, the most common was polysaccharides-based materials, which were used in the bio-consolidation of paper, and this was due to the compatibility in their characteristics with paper. Essential plant oils (tea tree, lavender, and thyme oils) and Chitosan are the most common biopolymers used as antimicrobials. Japanese papers and bacterial cellulose are the most appropriate materials for consolidation and completion of the missing and fragile parts of the papers and leathers. Polyurethanes, a synthetic biomaterial, were used as a coating to protect the leather from gas pollution. Beeswax protects the leather from pollution such as sulfur dioxide. This study is considered a guide for all conservators working on paper manuscripts and leather binding.