AluminumAluminum (Al)-ceriumCerium (Ce)-nickelNickel (Ni) alloys have proven extremely successful in producing stable intermetallicsIntermetallic that maintain mechanical propertiesMechanical properties at elevated temperatures. However, much of this success requires high amounts of alloying elements, such as zirconium (Zr), for adequate baseline mechanical propertiesMechanical properties, which can be costly. A practical and cost-effective way to enhance the mechanical propertiesMechanical properties of an alloy is by reinforcing it with ceramicCeramics particulates. Therefore, this study characterizes the effect varying additions of Zr have on a hypoeutectic Al–Ce–Ni alloy reinforced with sub-micronSub-micron (300 nm) aluminaAlumina particulates. The comprehensive characterizationCharacterization of this alloy includes Thermocalc™ simulationSimulation, SEM, EDS, XRD, and tensile testing. Metallography revealed the presence of the Al4CeNi phase in a metastable state. Direct aging at 400 °C for 10 h transformed the ternary phase to two binary eutectics: Al11Ce3 and Al3Ni. Additionally, aging directly affected the alloys’ mechanical propertiesMechanical properties with a correlation to Zr content. The tensile properties of the low Zr alloy (0.28 wt.%) improved by 15% and 49% in ultimate tensile strengthTensile strength (UTS) and yield strength (YS) (112.5 and 73.6 MPa), respectively, after aging. Increasing the Zr content (0.28 to 0.5 wt.%) resulted in improved UTS and YS of 19% and 14% (to 107.1 and 58.3 MPa), respectively, as-cast. After conditioning, the compositeComposite alloy’s UTS and YS increased to 135.6 and 91.2 MPa, respectively. This research identifies the compatibility of Zr and aluminaAlumina. It also emphasizes the potential for Al–Ce alloys as a foundation for castMetal-matrix-composites metal matrix composites.