Nanocrystalline cellulose (NCC) has gained much popularity over the last decade as a preferred nanomaterial in varied applications, despite its laborious industrial production and higher cost. Its production methods have undergone a great deal of metamorphosis lately. The main emphasis has been on the environment-friendly and green processes, in addition to the sustainable and renewable feedstock. Globally, the researchers have explored biomass and waste cellulosic materials as renewable sources for NCC extraction. Newer and/or improved process alternatives, e.g., ultrasonication, enzymatic hydrolysis and mechanical treatments have been applied successfully for producing high-quality material. Detailed investigations on optimizing the overall yield from cheaper feedstock have yielded obvious benefits. This is still work in progress. The present review majorly focuses on the advances made in the NCC preparation field from biomass and waste cellulosic materials in last three years (2016 - till date). Collaborative efforts between chemical engineers and research scientists are crucial for the success of this really amazing nanomaterial.