Cellulose, the most abundant natural polymer in the world has many desired properties such as biocompatibility, biodegradability, durability, low cost, etc. But it lacks some of the versatile properties of synthetic polymers like compatibility, melt-processability and solubility. To mitigate these drawbacks or to produce new sustainable products, chemical modification of cellulose becomes necessary in most cases. Introduction of synthetic polymers with specific properties onto cellulose via radiation-induced grafting is one of the key approaches to modify its physical and chemical properties. Utilizing reversible-deactivation radical polymerization (RDRP) methods in radiation induced grafting may provide unique opportunities to tailor the surface properties of cellulose by controlling the graft length and architecture. Nanocrystalline cellulose (NCC) is of prime importance as it constitutes a bridge between nanoscience and natural cellulosic resources. The modification of this nanomaterial via radiation-induced grafting approach represents a striking potential to be explored by academy and industry. In this article it is intended to highlight the recent works on the modification of cellulose and nanocellulose via radiation-induced graft copolymerization by conventional and RDRP methods.