The environmental issues caused by the usage of petroleum-based plastics have become a major concern these days. The depletion of the source is also being put into consideration for the use of the polymeric material. Thus, a biodegradable and sustainable resource for polymer filler, which is considered as waste, is brought into the study. Besides improving the polymer properties, the use of waste substances will reduce environmental pollution. For this study, the CaCO3 was derived from waste eggshell and used as fillers in a polypropylene matrix. The eggshell was subjected to grinding to obtain the powder form, the commercial form of CaCO3. The compound was molded using the hot press machine after being mixed in an internal mixer. The samples were subjected to several characterizations and testing such as Fourier Transformation Infrared (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Tensile test. The effects of filler size of 20μm, 50μm, and 100μm at 30 wt% eggshell powder content on morphological and other properties were studied. The FTIR and XRD analysis identified the reaction between the filler and matrix. For the composite, the tensile modulus increases with the decrease of particle size. However, the tensile strength decreases with a decrease in particle size. The elongation of the composite with 50 μm filler size shows the greatest value, followed by 100 μm and 20 μm. The filler morphology and fractured surface of the composite were studied using SEM and determined to have well-dispersed particles with fibrillated fracture surface for 100 μm and 50 μm while 20 μm have a smooth surface.