This study investigates the physicochemical properties of cellulose nanocrystal (CNC) -reinforced hydroxypropyl cellulose (HPC) hydrogels. HPC is a cellulose-derived, thermo-responsive polymer that forms physically cross-linked hydrogels near body temperature, while CNCs are rigid, rod-like nanocellulose particles that serve as effective mechanical reinforcements. The viscoelastic properties of the hydrogels as a function of temperature were characterized by rheological studies. The temperature induced phase transition was studied with dynamic light scattering (DLS). The adsorption of HPC onto CNC was analyzed with quartz crystal microbalance with dissipation monitoring (QCM-D). The incorporation of CNCs into the HPC hydrogels significantly enhanced the gel strength through physical entrapment and steric hindrance, stabilizing the network structure above the gelation temperature. The ionic strength of the solvent influenced gel properties, with CNC colloidal stability playing a crucial role in reinforcement. Preliminary cell viability tests suggested that CNCs improved osteoblast compatibility, supporting the potential of CNC-reinforced HPC hydrogels as biocompatible scaffold materials for bone tissue engineering.