With the advent of newer technologies in the electronic and telecommunication sectors, the extent of electromagnetic (EM) pollution is growing at an alarming pace. This is mostly due to the intermixing of EM signals emitted out from electronic modules that are mostly powered by microwave radiations. Hence, there is humungous interest among researches to design and fabricate high-performance microwave-absorbing materials that can address this undesired phenomenon. In this context, plant-derived cellulose nanofibers are considered as one of the most promising bionanomaterials for designing next-generation sustainable microwave absorbers. Nanocellulose can be utilized to fabricate flexible, robust nanopapers and highly porous aerogels that can find potential application as efficient microwave absorbers. This chapter encompasses on various strategies adopted to design and fabricate conducting nanocellulose-based functional constructs by incorporating various 1D and 2D nanostructures. The potential ways to enhance the overall microwave absorption by these shields has also been discussed in detail.