Nanocellulose, which is cellulose in the form of nanostructures, has emerged as one of the most significant green materials of our time in recent years because of their appealing and exceptional characteristics such as abundance, high aspect ratio, improved mechanical capabilities, renewability, and biocompatibility. The present review mainly covers the effect of different properties of nanocellulose on the mechanical properties of nanocellulose-based multiscale composites. Our review article covers the classification of nanocellulose structures, extraction of Nanocellulose, and mechanical properties of cellulosebased multiscale composites such as tensile, flexural and impact, followed by the applications of nanocellulose-based multiscale fiber reinforced polymer composites. There is a demand in the industry for an efficient alternate material to man-made synthetic materials with superior mechanical properties.Nano cellulose-based multiscale composites can be an efficient alternative to meet sustainability goals without compromising performance.