Nanocelluloses have gained significant attention in recent years due to singular properties (good biocompatibility, high optical transparency and mechanical strength, large specific surface area and good film-forming ability) and wide-ranging applications (paper, food packaging, textiles, electronics and biomedical). This article is a comprehensive review of nanocelluloses from the preparation methods to their applications in conservation and restoration of historical paper documents. The novelty lies in the information collected about nanocelluloses as renewable, environmentally friendly and sustainable materials in the field of preservation of cultural heritage as an alternative to conventional methods. Several studies have demonstrated that nanocelluloses, with or without other particles, impart to the paper documents excellent optical and mechanical properties, very good stability against temperature and humidity aging, stronger antibacterial and antifungal activity, high protection to UV light and do not require additional adhesive.