In the present investigation, AA6351 aluminum alloy matrix composites reinforced with various percentages of AlN particles were fabricated by stir casting technique. The percentage of AlN was varied from 0 to 20% in a step of 4%. The prepared AA6351-AlN composites were characterized using scanning electron microscope (SEM) and x-ray diffraction (XRD). The mechanical properties such as micro-hardness, compression strength, flexural strength, and tensile strength of the proposed composite have been studied. X-ray diffraction patterns confirm the presence of AlN particles in the composites. SEM analysis reveals the homogeneous distribution of AlN particles in the AA6351 matrix. The mechanical properties of the composite were found to be noticeably higher than that of the plain matrix alloy due to augmented particle content. The produced composites exhibit superior mechanical properties when compared with unreinforced matrix alloy. Fracture surface analysis of tensile specimens show the ductile–brittle nature of failure in the composites.