A green approach to anchor silver nanoparticles (AgNPs) onto the surface of cellulose nanocrystals (CNCs) coated with mussel-inspired polydopamine (PDA) at room temperature in the absence of a stabilizer and a reducing agent is proposed. The resulting nanohybrids possessed a core-shell structure with numerous satellites of silver nanoparticles decorating the CNC surface. The nanocatalyst displayed superior dispersibility over pristine AgNPs and was six times more efficient in catalyzing the reduction of 4-nitrophenol. By associating the CNC hybrid with beta-cyclodextrin to promote host-guest interactions, the catalytic process was accelerated. The associated physicochemical parameters associated with the catalytic process were investigated and compared.