Cellulose nanofibers (CNFs) derived from woody biomass have recently been expected as a key natural nanomaterial to establish a sustainable carbon-free society; however, we still have a long way to go. Current challenges to expand the possibilities of CNFs have focused on manufacturing high-strength, lightweight composites using CNFs as an alternative to conventional fillers, eventually resulting in serious competition going forward. CNFs have a diverse array of structural characteristics at the nanoscale that can never be artificially reconstructed, and we have to find out the unrivaled functions of CNFs both from tangible and intangible aspects. This article introduces the organocatalysis and biomedical applications of wood-derived CNFs based on the unique nanoarchitectures to provide a new insight into creating new values of CNFs toward the Sustainable Development Goals.