Cellulose nanocrystals (CNCs) are a new class of biodegradable nanomaterial derived from the most abundant and renewable biomass on the planet: cellulose. Due to their potential as a low carbon footprint nanomaterial, CNCs have received significant interest in the community for a wide variety of applications. In this review, we therefore summarize the most recent strategies exploited to produce CNCs, focusing on the “greener” isolation methods aimed at minimizing the environmental impact of their production. We qualitatively evaluate the environmental impact of each CNC production method and discuss the properties of the CNCs obtained. Finally, we discuss the necessary steps to address the development of the field in the industrial context, focusing on the type of applications where the CNCs can be exploited.