A novel approach in the production of protein based films and composites were performed, using the bovine milk protein casein and regenerated cellulose fibres (lyocell). The films were prepared by first dissolving the casein protein in an aqueous alkaline solution in the presence of glycerol as a plasticizer. Further the composite films were prepared by the addition of fibres on aqueous alkaline solution with casein. The casein films and composites were thereafter prepared by casting the solution mixture on Teflon coated glass plate and drying for 48 hr. The effects of glycerol content and lyocell fibre reinforcements on the mechanical, thermal and physiological properties of the casein films were characterized. The results revealed that the increase in the addition of glycerol content decreases the tensile strength, young’s modulus, thermal stability of the film and increases the elongation percentage. Tensile property and thermal stability of the films was improved by the increase in the addition of the fibre content with a gradual decrease in the elongation percentage. The casein film made of 20% glycerol and 20% fibre content showed the maximum tensile strength of 23.5 MPa, E-modulus of 1.5 GPa and glass transition temperature (Tg) of 67.1±1.5 ºC. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicated that there was no significant change in the molecular weight of the protein during sample preparation. The inter molecular networks have taken place in the casein films and composites, when analyzed under Fourier Transform Infrared Spectroscopy (FTIR), and proper bonding between fibres and protein was observed by scanning electron microscope (SEM).