Metal matrix composites (MMCs) are a type of sophisticated materials including a metal or alloy matrix blended with a reinforcing phase, which may exist as particles-whiskers, . Hybrid metal matrix composites (HMMCs) are sophisticated types of materials that utilize various reinforcing agents to improve the characteristics of the underlying metal matrix. Hybrid aluminum metal matrix composites (HAMMCs) are a specific category of metal matrix composites that utilize aluminum or its alloys as the primary material and include two or more distinct forms of reinforcements. The primary objective of this work is to investigate the mechanical and microstructural characteristics of hybrid composites consisting of Al6061, GNPs, and CeO2. The Al-6061 alloy is used as the matrix material, while graphene nanoplatelets (GNPs) and cerium oxide (CeO2) are used as reinforcing agents. The hybrid composites were produced by employing a 2-step stir-casting technique with proportions of 94:1:3, 96:3:3, and 94:3:1 of Al-6061: GNPs: CeO2. The 96:3:3 proportion was found to be the best which has a 24.47% increment in hardness value having the lowest grain size of 6.36nm. The maximum mechanical properties such as tensile strength (148.239 MPa), flexural strength (265 MPa), and impact strength (13.062 Joules) in the same proportion HAMMCs specimen.